I want to upgrade my 88 IROC to a disc brake rear end but am on a tight budget. I have a couple questions on what to look for. The car is basically stock other than a carb'd 350 and has the stock 700R4 tranny.

First, is a rear from a Fourth-gen car a direct bolt-in? Other than the 28-spline axles, is there any advantage to the later rear? They seem to be easier to find than the Third-gen disc rears.

Is there anything to watch out for on the later rear ends and what should I be expecting in terms of other problems?

Thanks for any info.

Info in the following link may be useful:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

they are not any stronger then third gen rears. those 2 splines dont have that much of a gain. and the rear will be off centerd to the drivers side. you would need a after market pan hard bar to center the rear. it is also a little wider then your stock rear so third gen wheels will stick out slightly

Getting a fourth gen rear is also a good opportunity to get 3.42 gears, I got my rear end from an 2002 v6... It came with disc brakes that bolted right on to the original brake line on my 91 and it had shorter gears which really helps my 305... I can only imagine it will do wonders for your 350...

Thanks for the info and links. JamesC's links were awesome!Couple more questions tho...

The centering issue only occurs if you lower the car, correct? otherwise, it sounds like the stock panhard bar would be ok (?)

Will the wider rear cause interference issues with the body? My car runs the stock 16" IROC wheels and stock springs. I'm ok with the wider track as long as I don't have rubbing issues.

Yes and yes.

Here's some info and pics of thirdgen wheels on fourthgen rears.

https://www.thirdgen.org/forums/auto...t-4th-gen.html

JamesC