After serious considerations of many options, ive decided it would be most fun/challenging/gratifying to rebuild my 7.5 rear in my 83' Delta for the purpose of putting lower gears (Dorman brand 3.23) to replace the stock 2.41s.

This car is just my DD that I would like to take into the next decade but also not limp down the road without 4 barrels.

The current setup has ~95k on it. Could I use the stock diff w/ 3.23s and save some coin

or

is it worth it to buy a new/used limited-slip or posi for a DD. I just dont want the build to nickel and dime me.

opinions welcome

 

Just throwing it out there, but the rear axle from 77-96 B-Bodies will all interchange with your car. May want to consider finding a used 8.5" (stronger) B-body rear before venturing into this. I understand you have the 7.5" which means you probably have 4.75"x5 bolt pattern. A new set of axles can address that or a drill guide. For what it's worth, I do have an 8.5" 3.23 open disc brake rear for a B-body ready to bolt in with both bolt patterns drilled. BUT, 2.41 to 3.23 will wake the car up a LOT. My neighbor has an '84 Caprice with a 305 and had 2.73 gears. It can actually do a real burnout now and moves around the city a lot better with the 3.23.

 

Yeah, I will agree that the rebuild is a tall order, especially after discovering this morning that I would need a new carrier. Out of curiosity, what are you looking to get for that rear you've got.

 

I have a 1993 axle but also with the 5 x5 bolt pattern, drums and a 3.42 open. Near Chicago. Axles would need drilling for 4.75 and machining the center smaller. $100. Cheers.

 

I'm confused by what you mean by this....

 

I think your wheels have a 2 3/4" center hole and the larger 5" bolt pattern uses a 3" center hole. Therefore the axles would have to put on a lathe and machined down to 2 3/4".
I think any machine shop can do this and also drill a set of lug holes on a 4 3/4" circle.

 

 

Most S10 4x4 pickups came with 3.42 gears as well. If you find a ZR5 those should be 3.73 gears.

But...I liked the 3.23 gears with the 3 speed trans. I installed them in my 80 cutlass up from a 2.28. You wanna talk night and day difference....lol. I got the posi carrier and gears from a mid 80's Camaro. YMMV.

 

Music to my ears. My dad recently bought an 85' Astro that he has already planned on changing out the [now known] 7.5, so he has got me covered on that now.
My first thought would be to just swap everything over while maintaining shim locations for a good start on pinion depth and bearing preload and just keep old races. Do you think it'd be close enough for comfort to use delta pinion races with the bearings from astro?

 

[QUOTE
But...I liked the 3.23 gears with the 3 speed trans. I installed them in my 80 cutlass up from a 2.28. QUOTE]

I also think getting rid of that horrible 2.41 should be your first modification contrary to what some think. My Custom Cruiser with a 3.23 is at least a bit snappier than others with those lame standard ratios.

 

If you are going to build the 7.5 rear axle, please do not use Dorman parts.

Cheap and will fail

 

Yes thank you. I opted to go for a set of used GM 3.42 ring & pinion off Monzaz page on ebay.
Also found myself a nice NOS series 3 open carrier to put them in.

I just havent taken the time to open up the diff yet as I don't wanna put more on my plate at the moment.