Trans build options in 2019

**04lss** · 05-20-2019

Hi folks,

I know there are plenty of threads on how to build a trans, but im finding that parts have gone out of production on certain things. Notably the 7/8" chain

my "plan" is to run a z3 turbo kit with the precision 6262 turbo on e85 etc making about 400-420whp

The idea would be to very ... VERY carefully run a stock HD trans while building another one on the side.

I know i would want to do the 300m input shaft.

My understanding is that the stock chain fails somewhere after 350? whp. I have been trying to source a 7/8 single chain, but it appears they are out of production now. I recall reading that the GXP chain is compatible and stronger.

A few questions:

1. Where do i source something like this

2. is it a double chain, or single?

3. will it hold 400whp

4. Can i just grab the trans from a GXP or v8 impalla?

5. What else do i need? Ive read that the flex plate potentially needs to be upgraded, and maybe the Torque converter? are there still good sources for these?

**tzerilli** · 05-20-2019

don't know answers to anything else but ive heard the ls4 trans is just as bad if not worse than ours and I don't believe it is a direct bolt in

**GTPpower** · 05-20-2019

Gxp chains are stronger than the 7/8. They are holding 500+. I've seen 7/8 chains stretch with as little as 300hp.

You can buy the gxp chains from dave or other parts. Hv093 is the part number.

They are double chains.

You can get them from an ls4 car...actually I think all 4t65e's 2005 and later had them. But they are about $100 brand new, so I wouldn't even mess with used chains.