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OVERDRIVE CONVERTION TO 1971 JAVELIN

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DHACKING View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DHACKING Quote  Post ReplyReply Direct Link To This Post Topic: OVERDRIVE CONVERTION TO 1971 JAVELIN
    Posted: Oct/01/2016 at 8:24am
WHAT SEEMS TO BE THE MOST POPULAR OVERDRIVE CONVERSION ON THESE CARS? IM LOOKING FOR A CONVERSION THAT REQUIRES THE LEAST AMOUNT OF MODIFICATIONS THE THE CAR ITSELF LIKE CUTTING THE STRUCTURE OF THE CAR AND/OR FLOORBOARD; TRANS TUNNEL ETC.
I'VE HEARD THE GM IS A GOOD ONE TO USE (4L60E) AND THAT ADAPTER PLATES ARE MADE.
DOES ANYONE HAVE AN ENTIRE KIT FOR THIS TYPE OF CONVERSION?
THANX IN ADVANCE FOR ALL THE REPLIES)
KIND OF NEW HERE...IM SURE THIS HAS BEEN ASKED BEFORE BUT I HAVEN'T QUITE FIGURED OUT THE SEARCH FEATURE HERE YET.
RAYMON H
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Post Options Post Options   Thanks (0) Thanks(0)   Quote oleblue69 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 9:00am
been running a GearVendors behind my 4 speed for 14 years, they also make for 727 automatic........etc
JS
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mramc Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 4:46pm
I've found after looking at them that gear vendors set is expensive for what it is.

Advance Adopters has a kit for the GM four speed over drive automatic. Novak adopters has better one in my opinion BECAUSE they give you a new flex plate in the kit ,which Advance does not. Also Novak has a very good web site with what they call a knowledge base that gives all the complete ins and outs of the swap. This comes up about every two months or so if you look here already there is a great deal of information on this forum . Modifying the floor pan depends on which GM automatic you use 400 or 200 based four speed and what car you putting it in. This swap has become so common we almost consider it a stock swap. Least ways I've let a car with a GM four speed automatic slip thru in a stock class, as you can not see it so what does it matter all that much in judging. But then that was a NAMDRA meet. LRDaum
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 6:40pm
Mramc, even though I agree 100% with your info... gearvenders is more than just an overdrive add on to existing 3spd automatics. Outside of the high torque and hp capabilites built in, it has a trick up its sleeve. All units have a computer to control engagement. Basically if you already have a good modded auto with a lower 1st gear, and a 2.87 rear... you can go under drive instead.

Let's total things up... computer controlled shifts, or manual override in any gear. So 1st gear will stay longer because overdrive will kick in, and the same for any other gear. Imagine 2 reverse gears as well. So with a custom 3spd with wide ratios, a gearvender will give you not just 4 different ratios but 6 depending on how you use the device.

IMO a gear vendor is not just over priced for a simple upgrade that requires shortening the drive shaft, and wiring up the computer if being used. It is a versatile option for high performance use without having to pay for a heavy 4L80E and some cutting to the tunnel.

71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 8:15pm
Is this a question concerning adding an over drive to an existing transmission or is it installing an automatic with an overdrive capability?
An 4L60E is an automatic transmission which is referenced to in the OP's question.
That being the case the 700R4 and it's baby sister family of the r200 is probably what is being asked about and their are adapters to install both of those transmissions and their later computer controlled versions. If space is an issue the 200 fits easier, if re-sizing the transmission hump is acceptable? I have a 700R4 in my Hornet and I am happy with it so far.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AMXFSTBK390 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 8:16pm
I have installed many overdrive transmissions in 50s-60s cars. Manual and automatic. My two favorites are the TKO600 and the 200R4 because of the final drive ratio being .68 and .67 respectfully. The 200R4 required no computer, no need to cut the floor in a 68 Camaro, and did not need to shorten the driveshaft. The TKO600 is a monster and I had to cut the '55 Chevy coupe floor for shifter clearance, and shorten the driveshaft.

Compare this to the Gear Vendors OD with a final ratio of only .78, and having to shorten the drive shaft, and shimming the rear end for pinion angle, and possible floor interference with the OD unit...decide for yourself. I did before installing a TKO500, TKO600, 200R4, and a Ford AOD. The OD ratio is far better on the open highway with the aforementioned transmissions than the Gear Vendor OD. Now, if I was building a drag car or big RV, I might consider the Gear Vendor OD.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DHACKING Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 8:32pm
THANX FOR ALL THE REPLIES. WHAT I WANT IS LOWER RPM AT HIGHER SPEEDS...AND I DONT WANT TO DO ANY CUTTING TO THE CAR AT ALL IF POSSIBLE. IM NOT ON A TIGHT BUDGET AND WILLING TO SPEND MORE MONEY TO GET WHAT I WANT. I WANT THINGS TO "APPEAR STOCK" IT SOUNDS LIKE I AM HEARING THAT THERE IS A UNIT THAT CAN BE ADDED TO AN EXISTING TRANSMISION; SO THAT IS A CONSIDERATION ALSO. IM NOT A FABRICATOR BY FAR AND SO WANT SOMETHING THAT IS MORE BOLT IN ETC...PREFER NOT TO GET INTO WELDING ETC. IVE JUST BEEN OUT OF THE HOBBY WITH AMC'S FOR 3 DECADES AND EXPECT THAT THE OPTIONS ARE MUCH GREATER THAN THEY WERE IN THE 80'S.
BOTTOM LINE....EASIEST INSTALATION BECAUSE I DONT LIKE THE IDEA OF ANYONE TOUCHING MY CAR/CARS......69 AMX AND 71 JAVELIN.
COMPUTER CONTROLLED IS SOMETHING I MIGHT NOT BE ABLE TO HANDLE WITHOUT SOMEONE HELPING ME ON THE SIDE.
COST ISN'T AND ISSUE TOO MUCH.
HOPE ALL THIS HELPS YA'LL KNOW WHAT IM AFTER.
I KNOW THERE IS PROBABLY A LOT OF INFO ON THIS SUBJECT ON THIS SIGHT BUT I HAVEN'T BEEN ABLE TO FIGURE OUT HOW TO FIND IT.
THANX AGAIN TO ALL!!!!
RAYMON H
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 8:57pm
Since you have a 71, I donno on what options are available with the BW tranny, if there is such a thing.

Since the pilot bushing diameter limits you to Pre 72 automatics or any year manual... going with a TH200R4 and adapter kit will be your best option though I would look into gear ratios... as it has a pretty steep 1st to 2nd gear set. There is some mods to change it to fit better with engines with good torque and gears. Some complain of 1st being way to low to be a performance boost because of how their rear was setup to begin with.

I chose a 3.25 gear for my rear because of AMC v8 torque and a wee lower than stock 1st gear. If I were to get a gear vendors overdrive, my gearing would be very close to a 3.55 in OD final drive with the 200R4. Sure the R4 will pull harder in 1st, but there will be a ton of wheel spin before you would be able to pull faster than my setup.

I once had a 73 Javelin with a Mopar 2.76 rear. I got around on the on ramp to the free ways at 55MPH in 1st near 4900 RPM. 2200RPM at 55MPH. TOP speed 142 MPH. I had a probe GT try and pass me as they max out at 138MPH. Once his nose got out of my draft, he fell back and could not keep up. A 304 has pretty good torque being a mostly stock setup. Stock valve springs are the weak link and limit better performance above 4500RPM.
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ARIZONAAMX Quote  Post ReplyReply Direct Link To This Post Posted: Oct/01/2016 at 10:45pm
I installed a gear vendors in my 68 AMX behind a 727.What a night mare.It might work on a longer wheelbase car.The driveshaft wound up being very short which caused a problem with the pinion angle.By the time I gave up on it I had hacked up my tunnel severely thinking just a little more will do it. I tried a lot of pinion shims but could never get rid of the driveline vibration .I regret doing this to my car.I sold the unit & was glad to see it go.
68 AMX 401,727.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Oly_Fab Quote  Post ReplyReply Direct Link To This Post Posted: Oct/02/2016 at 10:33am
There is another route. The AW4 from a jeep cherokee. I have been using this trans behind V8's for years. Bolts rite up no adaptors needed. It is electronic BUT Raddesigns makes shifters to get around that. I currently run a RD modified Winters shifter.
All you would need to do is find a 2wd jeep cherokee can be from XJ/MJ/ZJ with the 4.0/auto and get the trans/flexplate. Get the 4.0 flexplate match balanced to you old one. Figure out trans mount and driveline and what shifter... done.
P.S when you go this route you get to use the smaller starter from the 4.0

Stu
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