727 Kevlar & sprag

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   Hello, I'm slowly continuing my 79 Spirit drag car,2800lbs. I have collected most of the major engine parts and now getting into the trans parts. With a 360 engine making close to 470/480 hp are the Kevlar bands a necessity or a least make the trans more durable. Also thinking of putting in the bolt in rear sprag. Can you guys that are racers give me your thoughts on using these type of parts. Thanks Paul 

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xspiriment Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Nut Joined: Apr/27/2009 Location: New Mexico Status: Offline Points: 379	Post Options Post Reply Quote xspiriment Report Post Thanks(0) Quote Reply Topic: 727 Kevlar & sprag Posted: Jun/17/2016 at 9:32am
	Hello, I'm slowly continuing my 79 Spirit drag car,2800lbs. I have collected most of the major engine parts and now getting into the trans parts. With a 360 engine making close to 470/480 hp are the Kevlar bands a necessity or a least make the trans more durable. Also thinking of putting in the bolt in rear sprag. Can you guys that are racers give me your thoughts on using these type of parts. Thanks Paul

garland performce Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Nov/19/2013 Location: sibley mo Status: Offline Points: 172	Post Options Post Reply Quote garland performce Report Post Thanks(0) Quote Reply Posted: Jun/17/2016 at 11:38am
	Bolt in sprag a good ideal there a few bands to pick from A 4.2 apply lever for second gear band also a after market band strap call A&A trans 317-831-3066 they can set you up with all your trans parts

1970390amx Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/11/2008 Location: colorado Status: Offline Points: 3314	Post Options Post Reply Quote 1970390amx Report Post Thanks(0) Quote Reply Posted: Jun/17/2016 at 1:38pm
	I would use a 998 style trans. I dont think you have enough power to break it, they are lighter and use less horse power to run and would fit better in your car.
	1970 390 4speed Bittersweet shadow mask AMX 1970 Amx missing most everything, or in a box

Traveller Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Feb/26/2011 Location: Idaho Status: Offline Points: 1011	Post Options Post Reply Quote Traveller Report Post Thanks(0) Quote Reply Posted: Jun/17/2016 at 3:26pm
	Ditto on the 998. It's worth quite a bit to the ground, spins up quicker. 5.0 apply lever, Kevlar bands, low 1st/2nd gear set.

Hurst390 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/20/2008 Location: secret Status: Offline Points: 5814	Post Options Post Reply Quote Hurst390 Report Post Thanks(0) Quote Reply Posted: Jun/17/2016 at 5:01pm
	A 904/998 tranny uses a small pump drive on the torque convertor and is very prone to break. I've broke atleast 3. If you go that route you need a high quality convertor. Kevlar band is unnecessary. You can make your own bolt in sprag out of the one you already have with a transfer punch set and a drill press. I copy what A+A does and that is drill the sprag housing for 1/4-20 socket head cap screws and you use 1/4 brass Ferrell's on the bolts to take up the difference between the bolt size and the bolt hole. Or buy one for about 100 bux.
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xspiriment Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Nut Joined: Apr/27/2009 Location: New Mexico Status: Offline Points: 379	Post Options Post Reply Quote xspiriment Report Post Thanks(0) Quote Reply Posted: Jun/17/2016 at 9:54pm
	Thanks for the answers, I agree that a 998 would work fine, but I only have one 998 and its in a 79 AMX. I want to that as a running car and not rob the trans from it. The 727, I have two and one is already been rebuilt and sitting on the garage with a 4k stall converter. It was rebuilt about 10 years ago during another project and never used, so I'm going to pull it apart,check everything and install a bolt in sprag. II have some time working on it so I can get replies about the Kevlar bands and make a decision when going back together. It seem to be a toss up on the bands. Thanks for the comments. Paul

Hurst390 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/20/2008 Location: secret Status: Offline Points: 5814	Post Options Post Reply Quote Hurst390 Report Post Thanks(0) Quote Reply Posted: Jun/18/2016 at 9:15am
	You buy whatever you want! But since you asked for advice, in my experience building a couple hundred torqueflights I have never seen a band failure from a borg-warner or raybestos band. 4.2 front band lever A+A sprag If your gonna tow it around the pits or anywhere much at all I recommend a roller governor support. If your gonna run a stock valve body install the transgo shift correction kit with the manual valve. http://www.makcotransmissionparts.com/A727.html
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shootist Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: May/24/2012 Location: Triad, NC Status: Offline Points: 1023	Post Options Post Reply Quote shootist Report Post Thanks(0) Quote Reply Posted: Jun/25/2016 at 11:06am
	I had a stock 998 which I destroyed 2nd gear in with a 475HP 360. I replaced with a 727 because of future upgrades to power. I spoke to my trans builder when I rebuilt the 727 got lucky as it had a manual valve body with reverse shift pattern so save me some $ there. Anyway, the cost of building a 998 to handle the 475 HP I found to be very cost prohibitive and I can say for a solid fact that the power loss difference that I experienced between the two transmissions did not equate to even 1/10th at the strip. Now, depending on your application and what you are trying to accomplish I would just use a freshly rebuilt 727 with a stall to match your cam and a manual valve body to firm up shifts. However, if you are actually running in a competitive class like super stock where every 1,000th counts and money is no object you can't beat a built up 998. However, if you want cheap/reliable and don't mind crossbreeding you can look for a Turbo 400 with the AMC case.