irockid43

Hey guys, I know its been talked about a lot, but I need some advise on my rear axel options.
I have an 86 IROC, it has a 2.73 open diff with stock drum brakes. I found a 3.23 Posi with discs for a couple hundred bucks out of a 93 Z28. I
I would love to do the upgrade, but not sure of the wider axel look. I was hoping to get some advise and see some pictures of 3rd gens with 4th gen rear ends to see if I like the look.
Thanks!

irockid43

Typo *axle. Also, is it possible to swap out the disc brakes and the gears into my third gen rear end?? In order to keep the same axle with? Any info would be great. Or pictures and opinions.

skirkland1980

iTrader: (2)

What I did was put different rims on with more backspace.

skirkland1980

iTrader: (2)

If you want to see what yours will look like just use some nuts behind the wheel to space it out.

irockid43

Yeah, Ive been looking and that seems to be a nice look, Im not having much luck finding good pictures of stock wheels on a 4th gen rear end. (I have 16 inch IROCs) and would continue to run them for a while, but Id hate to do the swap and have them look terrible.

irockid43

THe nuts thing is a good idea! Thanks! Ill scope it out.

sofakingdom

iTrader: (1)

These cars look UNBEARABLY STOOOPID with the wheels stuck out in space; people will laugh at how "poseur" it is.

However, a 4th gen rear with 4th gen (or Vette) wheels on it, fits GREAT and looks good.

Not sure how it could possibly be A Good Idea to downgrade a 4th gen rear to 3rd gen brakes.

Best program would be, if you get that rear, use it as-is, and get wheels with the 4th gen backspacing.

big gear head

Your '86 has 26 spline axles, the 4th gen has 28. You can put the 4th gen parts in your 3rd gen housing, but you would have to upgrade the axles too. The 4th gen axles will not fit in the 3rd gen housing. Don't think that this is just a bolt in. You have to set the pinion depth, bearing preload and backlash any time you change gears, even if you are just taking them out of one housing and putting them in another. You can adapt the brakes. It requires some cutting and drilling on the housing ends, but it can be done.

irockid43

Thanks for the replies. I think Ill hold off until I can get the fourth gen wheels with the fourth gen rear end. I really like that look. I would love to get rid of these 2.73 gears. Im guessing that I will get a noticable performance gain switching to a 3.23?

big gear head

The 3.23 and 3.42 are good all around gears. They work great on the street and on the highway with overdrive.

sofakingdom

iTrader: (1)

Before buying that rear, determine ACCURATELY what gears are in it; use the only ACCURATE method that WORKS, which is, take off the cover and look. Reason being, some of that kind of car, came with 2.73 gears, if memory serves; no better than what you've got now. Also, the posi that would have come in it, was an Auburn, which isn't a real big thrill, but who knows, it might still be working. Again, take off the cover and look. There are NO SUBSTITUTES for taking off the cover and looking.

3rdgenmaro

iTrader: (9)

You didnt search very hard for pics.

https://www.thirdgen.org/forums/whee...end-stock.html

irockid43

Hey, thanks for the link. I didnt see that one. But the more I look, I can see that it is a popular topic. I appreciate all the info and opinions. I almost bought the rear end. Im going to wait and do it right. This site is awesome!
Thanks again!

lunati397

look for a set of 4th gen wheels get the spacers for the fronts only and forget your e brake and its a direct bolt in

lunati397

4th gen axle with 4th gen wheels (ss wheels can be bought for less than 500 now)

irockid43

Wow, That looks awesome! Really nice upgrade! I was just looking a some Corvette wheels on ebay. 17s in the front and 18s in the back. How do you guys think that would look on a third gen? I think these would look great on my red IROC.

http://www.ebay.com/itm/17-18-Black-...ede329&vxp=mtr

lunati397

search corvette wheels and you will find TONS of pictures there is a whole thread of just vette wheel pictures

lunati397

I had 275s 35 r17 up front and 315 35 r17 in the rear Nittos 555R DRs they fit without issue

irockid43

They look great! Did you install any aftermarket springs? Stock ride height?

Jeffs82TA

iTrader: (1)

My 4th gen V-6 has 3.42 gears and posi, I'm at 150k miles and it still works great. So your not limited to finding a 4th gen Z28 rear.