I am in the planning stages of a V-8 conversion for an 85 GT. I would like to keep an automatic in the car but I am concerned about the automatic handling the torque of the V-8. Is the bolt pattern on the 4T65E at all similar to the TH125C? Will the 4T65E be strong enough to handle 350 to 400 horsepower? Does the 4T65E have two chains? As always, any and all input is greatly appreciciated.
John
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08:47 PM
PFF
System Bot
Mr. Pat Member
Posts: 1860 From: Melbourne, VIC Australia Registered: Apr 2003
If your gonna do a 65, do the 65EHD. Its hard to find, but very strong. Im putting a 4T60-E bhind an LT1, and the beauty of both these trannys is the aftermarket. They can be beefed up more than the standard Fiero trannys. The bolt patter is the same BTW. An Archie adapter works fine. I had to trim the bracket a little, and the block to get it to fit, but it was minor. And that might just be LT1 specific. LMK if you have any more questions.
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09:27 PM
Powerstroke Member
Posts: 16 From: Gaithersburg, Maryland, USA Registered: Dec 2003
Your words are music to my ears and plans. We (my son and I) are planning on doing the Archie swap so it was good to hear the Archie adapter will work. As far as beefing up the 65EHD....can you recommend any places to go for parts? An LT-1 ...... sounds sweet, figuratively and literally. I think we're gonna go the ZZ4 route somewhere between 350 and 420 horsepower...now if I can figure out how to get twin turbos on it my dream will be complete (a bridge abuttment at 200 mph...not really). Thanks for the reply. Would love to see pictures of your LT-1 build.
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10:06 PM
Freshj Member
Posts: 1250 From: Holly, Michigan Registered: Nov 2001
Beefing up the 4T65EHD is easy. Just visit one of the many vendors for L67 parts. They have it all worked out already. Stronger input shaft, single chain, better TQ, LSD, Clutch packs, Shiftkits, and much more are all available. Good info can be found at www.clubgp.com . They will be able to answer all your 4T65 questions.
Don't forget that you will need a PCM that will shift and control the 4T65-E or any E tranny you use. You can get creative and use an S-10 OBDI computer to control it or order an aftermarket controller if you have the loot. All the S-10 PCM needs from the engine is a TPS signal and a distributor reference pulse plus power and ground and it should work fine, going to need a custom chip and maybe a VSS recalibrator module tho to make the VSS signal from the FWD trans compatible. Other than that, the 4T60 will work, as it is not electronic, but it is also not as strong as the 4T65-E.
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[This message has been edited by Darth Fiero (edited 12-30-2003).]
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01:41 AM
Powerstroke Member
Posts: 16 From: Gaithersburg, Maryland, USA Registered: Dec 2003
