I have a 97 that has drum rear brakes. I found a 95 z28 rear end that has disc brakes and posi unit for a good deal but about 1.5 hours one way. The guy does not know what gears it has it was a automatic. I was just wondering what options they had for that car. I only have 3.08 so I hope they are maybe a tad better.

 

i might be wrong but i think they are 3.42 for the auto make sure u check and makesure everything in good shape or u will be like me rebuilding the third member

 

There are several possibilities and there's really no way to tell without pulling the cover and dividing the pinion gear teeth into the ring gear teeth since the numbers on the housing will only tell you what was original and there's always the possibility that they've been changed.
My '93 Z28 has original 2.73's,many Z28s came with these highway gears so if you are looking for lower than your 3.08's you may well be going the wrong way.

 

I am also going this rought so I can have rear disc brakes and I want don't want to rebuild mine. I know I will have to pull the rear cover and locate the numbers on the gears. I am hope somthing is pretty easy to spot in their if something is wore out.

 

if metal comes out thats a good indicator its bad

 

Ask the seller to spin the pinion yoke and count how many times the yoke turns compared to the brake rotor turning only one revolution. For instance, if the yoke turns a tad less than 3.5 revolutions, he would have a 3.42. A little more than 3 revolutions, and it would be a 3.08, etc.

 

I thought the common options for the 4th gen z with an auto was 3.23's? My car had 3.42's with the manual. But then never know if they have been changed or if the car was ordered differently or something. easiest way to check is just how camaro 69 said. its not exact persay, but it will tell you if you are moving to a higher or lower set

 

yep gu5 is the common one and is a 323. gu2 is a 273. gu6 is a 342. if the guy has access the the option codes they should tell u what they are. the 342 was more common latter like 95 or something like that.

 

Well I emailed him back again and if everything goes right I will be heading that way today and pull the cover and see what I got.

 

The automatics had 2.73 and 3.23s, the standards had 3.42s