will a 4th gen rear end bolt in my 90 RS? If so, is stronger than the 91-92 Z-28 8.5?

 

Yes.

It will make 3rd gen wheels stick out about 1-3/4" on each side. 4th gen wheels will fit perfect.

There is no such thing as a 91-92 Z28 8.5" rear. However, the 4th gen rear is the same "strength" as the rear that DID come in 91-92 Z28s, which is the 7.5".

 

thanks for the reply. i was told that the 91-92 Z's had an 8.5, i didn't otherwise. my next question is, will the 7.5 hold up to my next motor which is a balanced 355 w/ Vortec heads, hypereutetic pistons, comp cams xtreme energy cam 268h .477/.480 lift, Edelebrock Performer Vortec intake, and an Edelebrock 600 elec. choke carb. approx 325 hp @ the flywheel.

 

That's OK, now you know the real deal.

As far as "will it hold up", that all depends on how you drive it. I've personally grenaded these rears with a 305, and the S truck guys (same rear) do so regularly with a 6-cylinder. On the other hand, I also have made one last pretty good behind a helluvalot stronger 400 than that 350 you're talking about. So that part is all up to you, the driver.