The answer is that 1/4 mile times are almost exactly the same as before, according to my admittedly unscientific testing method (a phone app), but the car feels stronger and actually burns rubber on take off now, which it didn't do before unless there was gravel on the road.  It seems to hold the gears longer than before-- maybe a little too long at full throttle-- though I don't have a tach on the car to verify that. Seems like the engine runs out of steam and that it might be a little quicker if the car shifted sooner. I guess I could shift it manually to verify that but I haven't tried it. 

Here's a little YouTube video I made of a short run up and down the hill outside my subdivision.  I tried to turn the volume up so you could hear the shifts.  I put a little GPS heads-up speed display on the windshield above the speaker grill though it's pretty hard to see in the bright lite and flickers in the video even though it doesn't when viewed live. 

The real benefit, as you might expect from the O/D gear, is on the highway. 70-75 mph seems like a comfortable cruising speed now compared to 65 mph before.  I calculate that the rpm dropped by about 800 at 70 mph.  Like I said, there is no tach in the car, but when I typed my tire diameter and gear ratios into a calculator that's the number I got.

You just do have enough gear for the OD. 87-90 models have a 0.705:1 OD, 91+ has 0.75:1 OD. There is about 120 rpm difference. With 3.15 gears, 26" diameter tire (215/65R15), 65 mph, .705 = 1865.4 rpm; same with .75 = 1984.5 rpm.  Typically you want to cruise at about 2000 rpm in order to be in the torque band with a stock or mild cam. You want to be about 200-300 rpm over where the cam "comes in" so you're in the torque band enough to pull the car without working the engine overly hard. Gives you 100-200 rpm to drop when the car starts pulling a hill before you have to push on the gas pedal a good bit more. With a 26" tire you're just there with the 3.16 gears at 70 mph (2137.2 rpm). If you have a bigger tire, say a 225/70R15 (27.4" diameter) you're still JUST there at 2028 rpm@70... but just under at 1883 rpm@65. If your cam is advertised at 1800-3500 rpm or something like that, I'd say the calculated 1885@65 is probably slow enough that the engine will work a bit harder, especially given some error in tire diameter and other drivetrain losses.

It won't strain, but will work enough harder that gas mileage will go down. I tried a 3.08 gear initially with my .70 AW4. Had to cruise at 75+ to be in a good rpm range in OD. I dropped to a 3.55 gear (what the XJ uses with an AW4) and actually gained an average of 2 mpg due to easier starts and being in the torque band. I would suspect a 3.31 gear would be near ideal for me (just a cruiser), but not enough difference for the expense of changing gears (I have a Jag IRS...  3.55 is pretty common, 3.31 was used only in some European models). Just a tad more gear like a 3.31 would be better for you, but I suspect a 3.55 would be more to your liking if you plan on any bracket racing. With a 27.4" tire (225/70R15) it would turn 2122.2 rpm @ 65, 2285.5 @ 70... only a 267 rpm rise @70.

I use the calculators at http://www.4lo.com" rel="nofollow - www.4lo.com for tire diameter and gear ratio. Just ignore the LT in front of tire size (Light Truck is the same sizing as a car tire, just a bit more aggressive tread design), and put in a "1" for transfer case ratio. Other calculators are pretty much the same, that's just an easy site to remember.

Thanks for the info, Frank.  I have an eight mile drive to town, most of which is at a 65 mph speed limit, with a slight uphill climb most of the way home.  I do notice that the TC drops out of lock-up mode when I hit the slope, but it stays in 4th and doesn't shift into 3rd.  Probably a 3.31 ratio would be perfect, as you say.

I had a crimp on the chassis ground of the TPS (pin D3 of the TCU connector) come loose at one point.  From the symptoms, I was pretty sure what the problem might be and found it quickly, but thought I'd share these symptoms in case anyone else runs into this problem.

* Shift points were a lot higher than usual, especially with light throttle in 1st gear.

* No kick-down when passing or climbing hills.

Basically with no TPS it seems all shift points become speed dependent, regardless of throttle position.

 

The torque converter locks up almost as soon as the transmission shifts into 4th gear. It will even happily lope along at 1,500 rpm with the TC locked up. This isn't a problem, but it's obviously programmed to maximize fuel economy.  Of course, you can always move the shift lever from "D" to "3" if you don't like this behavior while driving around town and move it back later for highway driving. Personally, I just leave it in D at all times.   

As soon as you step on the brake even a little the TC lock-up switches off and the rpm will rise slightly.  This makes for a quick way to check that the TC lock-up is operating properly, just give it light throttle and light brake simultaneously and you should hear (or see with a tach) the rpm rise.

With my 304 and the AW4 I averaged 17.2 mpg on my 700 mile trip to Las Vegas and back last month, much of the drive at 70-75 mph.

It's nice to know that even if all your electronics and sensors fail, the AW4 is still driveable. If the TCU fails, you can still shift manually with the shift lever.  If the TPS fails the shift points will be off, but you won't be dead in the water.  The TC lock-up defaults to "off", so if your brake switch fails it just means your TC won't lock up and your 4th gear revs will be slightly higher.  Your fuel mileage will suffer accordingly, but you'll get home.

If the AW4 could hold up to a 500HP hot street 401 and have a selection of torque converters it would be interesting.

Until then I just dream of a gear vendors unit for my switch pitch 400 turbo.

Here I thought I was the only one going that route... few have switch pitch 400 trannies and even fewer have the gear vendor setup. 

My local street racing buddies from the 80's were all Buick guys. We use to search the scrap piles and save any switch pitch trannies we could get our hands on as well as the smaller converters out of the cars with the switch pitch super turbine 300 which had a high stall speed of around 2800 rpms and low stall at 1800.

For a hot street car that stock super turbine 300 converter worked very well in a switch pitch 400.

It is all very easy to add to an AMC case turbo 400 if you know what you are doing.

The AW4 (Toyota A340) CAN be built to take 425-450 hp. You can get a complete performance built A340 from IPT (Import Performance Transmissions) for around $3k. It will last -- is run behind hopped up turbo Supras. At least the early models used the TV cable, though later ones used an electronic line pressure controller -- basically a servo motor with a link through the TV cable hole in the case that the computer controls. Wouldn't be too hard to lock the line pressure control in the high pressure position. As one of the guys on the Supra forums put it, "you have to hold your foot on the brake harder when stopped" (well, that's close to what he said...).  There are some slight differences between the AW4 and A340, but just calibration AFAIK. Anything that can be done to one should work on the other.  I'd contact IPT first though, as I know the bell is different and the pump input shaft could be a different length or splines, as well as output shaft. Their hi-po rebuild kits and valve body mods will work with the AW4 for sure.

The AW4/A340 is supposedly capable of 450 ft/lbs of torque stock, up to 650 modified (depending on level of modification). The twin turbo Supra guys run 450 hp, but the turbo I6 doesn't produce the torque that a 500 hp 401 would. TORQUE is the issue with a transmission, not hp.  So the trans can be built, and it's not as expensive as it once was. I think 501 Performane was the first US company to build them, can't really find anything on them and the AW4/A340 now, but the Performance Import Transmission site has a lot of info, and the two links below.

If $3K (+ shipping) for a performance replacement trans seems like too much money, you an always go the 2004R/700R4 with adapter route. Probably cost as much or more. I'd start looking for a 5L50/5L60 or 6L60 myself. The more gears the better! Those would probably be a bit on the expensive side though, especially since you would need an aftermarket controller, and the only one I found is $750.

http://www.importperformancetrans.com/index.php?l=product_detail&p=4341" rel="nofollow - https://www.importperformancetrans.com/index.php?l=product_detail&p=4341

http://www.supraforums.com/forum/showthread.php?267655-How-to-make-a-a340-last%2856kers-take-a-nap%29" rel="nofollow - https://www.supraforums.com/forum/showthread.php?267655-How-to-make-a-a340-last(56kers-take-a-nap)

http://www.jeepstrokers.com/forum/viewtopic.php?t=2236" rel="nofollow - https://www.jeepstrokers.com/forum/viewtopic.php?t=2236

http://www.naxja.org/forum/showthread.php?t=1055170" rel="nofollow - https://www.naxja.org/forum/showthread.php?t=1055170

PADDLE SHIFTER!!!   Bear with me a moment as I describe the rotary switch I've used to manually shift my AW4 for years. TV cable is still connected, but no shift computer. The rotary switch works well, you have to manually shift up and down. Put the shift lever in D (or OD if in a Jeep) and the trans starts in whatever position the switch is in. Simple to wire up using diodes for the logic. I have it wired to shift 1-4 with a rocker switch for the lock-up. The trans will not lock the converter in 1st, so I usually leave the lock switch on all the time. 2-3 shift is a bit hard, but if you let off the gas momentarily when shifting it's nice and smooth. The rotary switch works great as long as you have a console with armrest to mount it on so your hand naturally lies over the switch. Two disadvantages -- 1. If no conveniently located console with arm rest it's a PITA as there is no convenient place to mount it.  2. One hand is off the wheel, not good for performance driving. There is no worry about dropping into 1st at speed, or 2nd when in Drive. The trans only brakes in the top two gears -- 3-4 in D, 2-3 in "3" (IIRC that's the next down from D in the XJ). So you an drop to 1st from 70 mph and ride the brake to stop even with the lock-up engaged. I gear down for the engine braking to 3rd then drop through 2nd (even though no braking) down to first at the appropriate speed. That way if something unexpected happens I'm the right gear to get out of the way. If I dropped all the way to 1st from say 50 mph anticipating a stop (safe to do that) and for some reason needed to scoot out of the way, the engine would have to rev way up before the trans would engage due to the gearing for 1st. Going down through the gears I'd be in 3rd and ready to scoot. That's saved my butt a few times!!

I'd never seen this paddle shifter before! The logic circuit will of course work with any two momentary switches, paddles or push buttons. Real neat way to do things! I can't believe I never found it since it's a 2005 thread! But no AW4 reference, and A340 is only mentioned in the text a couple times, not in the subject. I knew Volvo used the trans in the 960, I had a 960 for a few years, but never thought to search Volvo forums!!  The link was found on the Jeep Strokers forum though... don't know how I missed it until now!!

http://forums.turbobricks.com/showthread.php?t=47229&highlight=paddle+shifter" rel="nofollow - http://forums.turbobricks.com/showthread.php?t=47229&highlight=paddle+shifter

CamJam got one, but I assume it's all about location. Bigger towns and cities may have them more available at pick and pulls and truck salvage yards.  Though I was in the impression like the th400, an aw4 can be converted to 2 wd with proper parts. Just need a good tranny shop to source parts if that is the case. 

http://Row52.com" rel="nofollow - Row52

Vehicle Search

1987-2001 JEEP

ZIP Code

SEARCH.

Click each result and look for RWD.

95/5 it's going to be issued an automatic.

The AW4 is a Toyota product with a detachable bell housing. The Jeeps are issued this transmission with the AMC bell pattern. I know, the answer is don't think about it. The more you try to figure it out the hard way the more it's going to hurt. Make sure you grab the output yolk and torque converter while you're picking.

It's not entirely correct to say the AW4 is a Toyota transmission. Though versions of it were used by Toyota and Isuzu, it was originally a joint development of AMC and Borg-Warner (now Aisin-Warner). If nothing else, it makes me feel better to know it has the AMC heritage. 

Here in the southwest I seem to find about 1 in 10 XJ Cherokees in the wrecking yards are 2WD, but there are a lot of XJs in the yards around here so that helps. Real problem is most have 200k+ miles on them. I lucked out and found an ex USFS vehicle with only 68k miles on it.

I might stop at the local U-Pickit tomorrow to see if they have any 2WD. If so, I'll post details here.

98 Cherokee, no stock # visible, no speedo but had 99k miles in 2005 according to an oil change sticker. Row 312

94 Cherokee, stock # 2986, 288k miles, no oil pan on tranny. Row 312. I took the pan off this tranny myself two months ago to replace my own, which had been repaired but still leaked.

93 Cherokee, stock # 3075,166k miles. Row 315

01 Cherokee, stock # 0396, no speedo. Row 319

So as u can see we do have some 2WD Cherokees available here in the southwest, but most of them have high miles now.

My aunt had a 2wd Jeep back in the late 80s.  Though she had to drive off road to get home, as she had farm land property in the back 40.

Most automatics will survive high milage up to 300K if properly maintained, even back in the 80s,  unless you got a GM TH125, which sucked for heavy usage, such as in mini vans... though many 4 doors ended up having issues as well, before 125k

Yep, the 125C is the better, just the 125 from 80 on to 86 sucked.  Had the 125c in my 95 Lumina.  Outside of the governor drive gear being trash (plastic) on the output shaft, that tranny put up with my abuse land it had over 170K.  Had to wire the blasted governor to bypass 1st so i coukd have 2nd ,else I had no 2nd at all. Which was a dog to get onto the highway. Outside of that, both the 2500 I4 and 125c were as durable as an AMC engine, when abused.

Great write up!  Hopefully, they will make this a sticky.  The one I wrote is pretty chopped up.

I have a 3.54 rear gear behind the AW4 in the Daughter's Javelin.  Still running and driving great.  I had found a couple of companies that can build the AW4 to handle more power but, I can't seem to find the links now. 

Here is some more reading on the AW4.  https://www.jeepforum.com/forum/f11/aw4-performance-write-up-273048/" rel="nofollow - https://www.jeepforum.com/forum/f11/aw4-performance-write-up-273048/

Scott, I'd forgotten the exact amounts I paid, but I got the following from their web site:

Transmission and torque converter: $150

Flex plate: $19

Control box: $22

Core charges too.  I seem to recall the grand total being about $230 for everything as I didn't have any cores, but that included $25 for the Jeep's shifter, which I ended up not needing. Figure approximately $200 for everything then.

http://u-pick-it-arizona.com/upaz/pricelist.php" rel="nofollow - http://u-pick-it-arizona.com/upaz/pricelist.php

I made sure that all the kick down/shifter cables and harnesses were attached to the transmission so that they didn't charge me separately for them. 

The TPS is a Standard Motor Products #TH143, which is for the same '94 Jeep Cherokee XJ that the transmission came from.  Also fits many other Chrysler products I believe.  As mentioned in the first post of this thread, I came up with a pulley arrangement to connect the TPS to the carburetor's throttle linkage.  I made the pulley from a couple of cupped shock absorber washers bolted together, and then cut a slit on the tip of the bolt with a 4" angle grinder so it would slide over the "tangs" of the TPS.  That provides the mechanical grip to rotate the recessed TPS "wheel".  I then glue the bolt in with epoxy, being very careful not to get epoxy between the rotating parts of the TPS.  Just to be sure, I rotate the pulley quite often as the epoxy is curing just to break the bond in case some got into the gap between the rotating parts of the TPS.

When you're done it should look like this:

Note that there is a hole drilled for the cable to pass through on the inside half of the pulley. I am using 1 mm wire cable to go from the pulley to the carburetor throttle linkage.  I found a kit on Amazon for about $8 that included 10m of cable and some lead crimps.  The bracket I'm using (see post one) allows the TPS to slide.  Set the TPS in the middle of the range of travel and then crimp the cable so that the cable has a little slack in it, but not so much that your cable unwinds from the pulley. You can then adjust the cable tension by sliding the TPS back and forth on the bracket. The Autolite 2100 on my car already had a hole in the linkage for the cable to pass through.  If not, you may have to drill one.

If the TPS is not functioning or improperly adjusted, transmission shift points will be off, "kick-down" may not occur and torque converter lock-up may not work properly.  If the TPS cable is too taut the car will hold gear too long before shifting and downshift even with light throttle applications or small hills, so I like to keep a little slack in it.

Also, don't forget to adjust the kick-down cable.  The procedure is exactly the same as for the Jeep XJ, assuming you've used a standard type cable mount like this:   https://www.napaonline.com/en/p/BK_7355230?cid=paidsearch_shopping_dcoe_google&gclid=CjwKCAjw0_T4BRBlEiwAwoEiATuSIJybytjAL-4zQBpGPMP9QgZ7eoOpNOwrN6hMQwjqB3Gi2LsxGBoCpnkQAvD_BwE" rel="nofollow - https://www.napaonline.com/en/p/BK_7355230?cid=paidsearch_shopping_dcoe_google&gclid=CjwKCAjw0_T4BRBlEiwAwoEiATuSIJybytjAL-4zQBpGPMP9QgZ7eoOpNOwrN6hMQwjqB3Gi2LsxGBoCpnkQAvD_BwE

Here's a tutorial on that adjustment:

https://www.allpar.com/SUVs/jeep/cherokee-transmission.html" rel="nofollow - https://www.allpar.com/SUVs/jeep/cherokee-transmission.html

There's lots of useful info on the Jeep XJ forums about these transmissions.   Over 3 million XJ's were built and the majority of them had AW4s!  Toyotas and Mitsubishi used a version of the AW4 as well, so parts should be around for a long time to come.

If you're running a Holley or other variant (Demon, Quick Fuel), there is a TPS retrofit kit available for about $100.

Bob

tufcj

Good tip, Bob... thanks!

There's one more issue that I needed to address.   As mentioned in the original post, a switch is needed to control the function of the lock-up torque converter.  This disengages the lock-up function whenever the brake pedal is depressed.  If no switch is installed, the lock-up TC is not functional (unless you were to permanently hard wire the circuit... NOT recommended). 

The Javelin's stop light switch can't be used (without a relay) as it's a normally open (NO) switch and the TC lock-up requires a normally closed (NC) switch.  I had been using ATV brake light switches I bought on Amazon, but they're of poor quality.  The first one broke after a year and the second one is getting intermittent now.  Fortunately, I kept the original brake light switch that I took from the Jeep when I got the transmission.  It has more poles than we need here (as I continue to use the Javelin's stoplight switch for the brake lights) and has both NO and NC poles in the same switch. An ohmmeter will tell you which poles to use.

I used a conduit clamp and a hose clamp to attach the Jeep's stoplight switch to the steering column.  I'm sure some of you guys could mill a bracket out of a solid billet of aluminum, but a trip to Home Depot is more in keeping with my capabilities.    Though a bit crude, it works surprisingly well. I also considered fabricating something using a tachometer bracket, so that's an option if you want something that looks a little more professional.  Since it's under the dash, I wasn't too worried about aesthetics. 

The button presses against the front side of the brake pedal shaft, which means TC lockup is always engaged except when the brake pedal is depressed.  You'll only need two wires, and the rest can be cut off.

Since the button was about an inch away from lining up horizontally with the brake pedal shaft, I also fabricated a little bracket on the brake pedal shaft that the button on the switch rides against.

It all works well and it's easy to test that it's operating properly.  You only need to drive about 45-50 mpg and step lightly on the brake pedal and you should see the revs increase by a few hundred rpm as the lock-up TC disengages. 

I'm using the factory stoplight switch on my 63 Classic, but mounted like the factory did on the pedal and brake rod. That's not a bad mount for the switch1 At this point I think I'd just ditch the original switch and use the one though, since it will work with brakes too. I have a manual controller on my AW4 -- having speed control issues (I think the rotor has lost it's magnet, the switch tests good but no speed signal).

I have a manual switch for the lock-up converter. You can just leave it on all the time. The AW4 won't lock the converter in first gear no matter what. The only issue with leaving the converter locked all the time is a hard 2-3 shift. I can turn the lock-up off momentarily or let off the gas when making the 2-3 shift for a smooth shift. If you don't turn the lock-up off or switch to first when coming to a stop, the engine will buck then stall -- just like trying to stop with a manual trans without using the clutch. It does this only at a low speed, and you have plenty time to flip the switch or switch to first with the manual controller. The controller is mounted on the center console and easy and convenient to reach. To use a manual lock-up switch with an auto shift controller you'd have to have the switch in a very convenient place, which isn't easy on most cars, and you'd have to be conscious of it.

When someone else has to drive the car (like for a front end alignment) I just turn the lock-up switch off and tell them not to use it. Doesn't hurt anything no to use the lock-up at all, just costs you 300 or so rpm when cruising. I have taken to leaving the switch off until getting into 3rd gear lately, and switching it off when down-shifting below 3rd. Have considered re-wiring my controller as a five speed -- 1, 2, 3, 3+lock, 4+lock. Not really enough jump with and without lock in 3rd, but it would eliminate thinking on that 2-3 shift (let off gas or turn off converter??). Would still leave the switch in as a bypass, but would no longer be needed. I'm using simple "diode logic" on the shifter -- wouldn't be hard to add the line for the lock-up to the gear positions on the switch.

First thing, thanks for doing this write up.  I'm in OD purgatory right now, trying to decide on the most practical, cost effective and longest lasting conversion I can accomplish.  I see that you posted this in 2018, any update on the conversion or things you might have done differently?  

I'd also be curious how much out of pocket this ran you and how many hours you estimate that you have into this swap overall?

Appreciate any guidance you can offer 

DMack

Dave, I don't think there's an easier swap, especially if it's a 72-74 Javelin.  Everything bolts up. The worst part is finding a 2WD XJ Cherokee for the donor transmission and getting the flex plate matched balanced to the old flex plate.  Not too many shops that can do that.

Remember that you need to grab the Jeep starter too.

The wiring to the TCU takes a little time, but it's nothing difficult.  I bought good quality crimps and crimpers and have had minimal problems.  One time the torque converter wasn't locking up, which I traced to a poor ground connection.  Fortunately, even if you did have a wiring issue or your control box dies completely you won't get stranded as you can always shift it manually.

I'm very happy with the results.  The gear ratios seem about perfect for my 304.  I've put about 5k miles on my car since the swap including two trips to Las Vegas and back, about 500 miles round trip each.

The only adjustments that need to be made after installation are the throttle position sensor and the kickdown cable.  Both affect the shift points and it might take a little trial and error to get them adjusted where you want them.  It's pretty intuitive once you get into it.

As for out of pocket... I'm guessing here as it was a couple years ago, but I think the transmission with TCU, Jeep slip yoke and starter was around $250 at the wrecking yard plus $100 to have the flex plate match balanced.  I also paid to rebalance my driveshaft because of replacing the original yoke with the Jeep yoke.  Not sure that is really necessary but it helped tame some vibration in my case. I think that was about $85. Transmission mount was around $10 or less as I recall and I bought a bracket kit for mounting the TPS and kickdown cable... somewhere around $20 for that I think.  Might be some more info earlier in the thread on that.

Hours?  I have no idea.  I paid a transmission shop to actually bolt the transmission in but towed the car home and did all the driveshaft and electrical connections myself.  I initially had some vibration issues due to a poorly balanced flex plate and that took a LOT of hours of troubeshooting that you won't have if your balancing shop knows what they're doing.

Good luck.  Feel free to PM me if you have questions once you get into it.

Thanks so much for the response.  

I'd probably get the trans rebuilt before I put it in my 73'  I'm pretty adept at the "mechanical stuff" it's the electronics that give me pause... first concern is I'm color blind, so I tend to stay way from wiring as much as possible.  It looks like you came up with really solid fixes and brackets for the TPS and kickdown cable issues.  I'm looking at going this route or (robbing a bank) and getting a Gear Vendors unit for my 727.  Cost is the major factor there.  I'll apologize now if I decide to go the AW4 route, because I'll probably have a ton of questions for you...  First things first, I need to see if I can find an acceptable donor vehicle...so 94-01 Cherokee 2WD XJ is the ideal donor?

Ideally 1991-97 (maybe 96-1/2?). Here's a great write up on the differences:

https://www.naxja.org/forum/showthread.php?t=1053970" rel="nofollow - https://www.naxja.org/forum/showthread.php?t=1053970

Must be 2WD version. 

From my first post in this thread:

I have an 87 AW4 with the 0.705 OD and 3.55 gears. I posted about my setup on the first page. My car cruises best at about 65 mph (best economy). That's due as much to wind resistance than anything else, which goes up exponentially over 65. I seem to recall the slip yoke being the same for all 2WD models, but there is a difference in the spline count for the output shaft of 4WD models into the transfer case.

Thanks for that, but I'm really no mechanic and just figured it out as I went.  I also had Rick Jones' informative sticky as a reference.

I drove the car to Colorado Springs to the AMO National last year, 1,600 miles round trip.  Even took it over Wolf Creek Pass.  I've had no problems with the transmission at all since the swap except for the one time mentioned earlier where I had a defective TPS.

I just bought a '73 Javelin (with a 727) too, and have been asking myself if I should put an AW4 into it as well.  Driving the two back to back has given me a good way to compare.  The 727 shifts fine, but yes, when I get up to about 50 mph I keep expecting it to shift to the next gear and (obviously) it doesn't.  

That's really the only major difference to me.  The AW4 shifts a little smoother, but I don't find the shifting of the 727/998 to be objectionable.  There is something to be said for keeping a car original, which is the reason I've held onto my original 998 transmission.

I guess it comes down to how much freeway driving you do.  Around town, there's no reason to have an AW4.  Here in rural AZ, with our 75 mph speed limit, there's a definite plus side to having an OD gear.  I'll have to decide soon as I'm planning to rebuild the 360 in my '73 later this year and that would be the ideal time to do the transmission swap.