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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: dunklin on December 04, 2013, 11:52:26 am

Title: 82,Chevy 454 Allison trans question
Post by: dunklin on December 04, 2013, 11:52:26 am
Hello, I'm new to the forum, I have a 82 long bed 4x4 Chevy, 454, granny low 4 speed, 410 gears. I was wondering is it possible to mate a Allison trans and transfer case to my BB. I'm looking for less rpm. And my existing t-case has, 2h,2l,n,4h, and 4l. I've owned several of these old trucks but have never seen a t-case like this with the 2h and 2l
Title: Re: 82,Chevy 454 Allison trans question
Post by: Engineer on December 04, 2013, 05:41:34 pm
Yes you can mount the Allison 1000 from a Duramax, or 8.1L truck to your big block. It is a monster so you may need to modify your trans tunnel, or put a body lift on it.

The Ally has O/D so you would be ok keeping your 4.10s.

What you may try is finding a later model NP205 transfer case that uses the later style round mounting flange. This case should bolt directly to the back of the Allison. You most likely will need to investigate the Ally's output, and the NP205's input. If the Ally has a 32 spline male out like the female NP205 will have with the round mount then you would be in business. However I have never done this build so I can't say for sure if it is a direct bolt on.
Title: Re: 82,Chevy 454 Allison trans question
Post by: pholliday1 on December 04, 2013, 09:18:52 pm
Might be a lot cheaper and easier to run a 480le with stand alone computer
Title: Re: 82,Chevy 454 Allison trans question
Post by: dunklin on December 05, 2013, 11:25:10 pm
I'm thinking of just dropping to a 3.42 axle, they told me today at the power train shop it should drop it around 600rpm. Def the cheapest route


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