84-Z28-Canada

Hi guys,
So I've read through the FAQ on the ten bolt. Garbage I know, but it's what I got. Here's the plan.. upgrade my 84 Z28 rear end (currently 3.23 open rear 7.5" with 26 spline axles) to a 3.73 posi with 28 spline axles. I'd like to keep my rear diff, so I don't have to buy new wheels etc as if I went with a 4th Gen rear. My question is, can I buy the 7.625" 3.73 gears and either a 7.625" Eaton Truetrac or Powertrax No-slip unit with the 28 spline axles (and then Moser or Ten axles) and have it all fit in my 7.5 rear that I already have, or do I need the bigger carrier to do all that upgrading? Thanks a million

big gear head

It will all fit your housing.

84-Z28-Canada

Thank you very kindly big gear head!

big gear head

The 28 spline Power Trax No-Slip will not fit in your 26 spline differential case (what you are calling the carrier). You will need a 28 spline case for that. I'd recommend getting a complete differential instead of using the No-Slip. Power Trax makes a Grip LS that should work well.

84-Z28-Canada

Oh OK, see that's what I've been unclear on. I'll look up the powertrax unit. Grip LS? Will that necessitate a 4th Gen rear?

NowhereFast

I put a 28-spline 4th gen Torsen Posi in what was a 26-spline rear, out of an 86 Z28 and used 28 spline moser axles. I don't know about the aftermarket diffs or why they woulldn't work, but everything went together perfectly.

big gear head

All of the 7.5 and 7.6 differentials will fit the 3rd and 4th gen housings. You just have to match them up to the correct axles and other parts. As long as all of the parts work together it doesn't matter if it's a 7.5 or 7.6 housing.