I have a 91 Z28 and blew out the rear gears at the track. I know the 10 bolt 7.5 in rear that i have is never going to be "good enough". I have looked around at rear ends and am thinking of putting in a late C4 (92-96) rear end assembly. Is this possible without MAJOR modification? Has anyone done it? What do you think? Please help its appriciated!

 

Only a 3rd/4th gen diff will fit because they use a torque arm. To install a C4 diff, you need to find some way to mount or eliminate the torque arm. Neither way is easy.

I'm not sure what the width of the C4 diff would be.

 

Rear end assembly? As in the whole IRS? It can be done, whats required, dunno. GM did it to a bunch of 3rd gens in their skunk works type programs. Along with the zf 6 speeds. twin turbo 350's, and 454's.

 

Dimensionally it fits in like it was made to go in a thirdgen.

U will have to make custom mounts etc.

Hardest part will be figuring out what your going to do with the rear spring in the vette IRS, do that and the rest is easy.

Torque arm wont matter at that point as running the IRS will eliminate it anyhow.

later
Jeremy

 

Ahh. I was thinking it was a solid axle. Do a search. I'm sure there's a thread somewhere about someone who did the conversion. I'm sure it will need some sort of major modifications. It's definitely not going to be a simple bolt in swap.

 

Kind of a day and night difference, they put straight axles is C5s because of the limited amount of abuse they will handle when modified, so i imagine the C4 set up would not be any stronger, the mounting hardware required would be a job to make i would imagine, old Stephen 87 IROC does some major work, give him a shout and see if he is up to it

 

eh... sounds like to much work for what i want... i did want independent rear so i could road race. ill just go 9 inch, unless you have another suggestion

 

have anyone pictures from this work...

I am about to by a rear end from a C4 now. but want to be sure this can be done before I go with it.

is there any weight saving if you change into a C4 IRS rear?