8.5" G-body rear wanted, or decent geard 7.5 carrier

[Russ Jerome]

I've got an 87 G-body with a 26 spline 7.5" Im gonna repower, nothing crazy 300hp. I have cash for a new locker for my rear that probably has crap freeway gears or spend it on a better housing or at least a better Monte SS carrier/gears and I will install a locker. Figured I would ask here before sending my cash to e-bay.

Any 7.5" donors with decent gears would be helpful if I don't find a bolt in 8.5" housing.

[Old Guy]

The SS set up will still be a 26 spline 7.5 set up, only the GN and the Hurst Olds have the 8.5. Simple but most cost effiecent is to get a posi off ebay and the only one you want is the late model Camaro or fire bird Torrison posi. This is a gear set up and comes with a 28 spline spiders. Then order a set of after market axels 28 spline from summit. With all the money you saved you can order a new rear gear of just get one off ebay, the blazers and S-10 came with any gear ratio you wanted down to the 4.10. Also if you still have some money left over you can get the reinforced differential cover to brace the caps.

[Russ Jerome]

Everybody says "late model" F body for diff, any specific gen to start with? Lots of different info online as expected.

[BAD LS1]

99+ f bodies were TORSEN diff's, they are the all helical gear lockers essentially. 98 and older used shitty auburn cone clutch posi's just as bad as the ford trac lok, minus clutch tabs in case.Use nothing from a truck 7.5, the eaton gov-loc is not a performance piece, unless you count the performance of parts shitting from it or the higher performance of one wheel than the other...

Later 2wd s10 you would be able to get 28 spline axles from, they have the same dimensions as the g body so I have heard, may as well rob the 3.73's or 4.10's from a 4 banger s10 while your in it for axles.

[Russ Jerome]

Best info Ive read in 2 days, thanks!

[Old Guy]

I did the TORSEN diff with the mosor axels on a 79 regal. Traded a guy a set of vortec heads for the axels and the diff was off of ebay for I think a $100. and the 3.75 gears were from a friends 4 cyl. S-10. With the regal I kept it a simple high school / weekend bracket car. Low 13s at 103 on a street tire.

[Russ Jerome]

Im not putting crap for power to ground so its an easy choice , just parts. To confirm I found RPO in glove box, says 2:45 or something like that, I need a diff.

[Old Guy]

If your leaving the stock 26 spline then just get a early S-10 that came with the 26s. It will have the correct carrier and you get your choice of gears already assembled on the carrier.

[BAD LS1]

You will have to find an 88 or older s10 to get 26 splines... Then only aftermarket posi's or some wore out oem unit, but s-trucks had gov loc's back then too, which are shit. Better off with the late model 28 spline, has to be a 2wd so the length is right, the 4wd's have a wider stance that matches 4th gen f bodies. GT4 code is 3.73 and GT5 is the code for 4.10 if you have access the the glove box sticker on the donor S10 4banger.

[Old Guy]

I might add two others if you want less then a 3.73 The GU6 is 3.42 and the GU4 is 3.23

[BAD LS1]

The 3.42 or 3.08 is the only other options found in a s series axle if it was a 6 banger 2wd. The f body TORSEN will come with 3.42, 3.23 or 2.73's wrapped around it.

[Russ Jerome]

Hows this for cheap: get the early s-10 26 spline carrier with decent gears but OPEN, add a powertrac or whatever spider type locking aid.
Just enough bite for strait line at track and I would maybe have $400 in setup when done?

[Russ Jerome]

Better off with the late model 28 spline, has to be a 2wd so the length is right, the 4wd's have a wider stance .

Are you saying the inner axles will seat in my housing? That's a cool trick if that's so!

[Old Guy]

I have not done the S-10 axels, I only went with the stronger moser axels when I did the swap. I suppose you could look up the length on a after market site or book and then cross reference it to a set of stock factory axels.

[Old Guy]

I was just over on Ebay looking the some posi units and prices. Punch in 7.5 Posi and a number of them will come up. There are several of the Torsen units complete with gears from 2.73 on down and priced under $200 complete posi and gears. Also a number of units for the 26 spline axels.

[Russ Jerome]

Im seeing that! Ive got to go to rad for temp spares today, gonna pull some RPO codes off S-10's while there.

[Rocket Power]

only the GN and the Hurst Olds have the 8.5.

Only the 84 H/O came with one and you forgot the 85-87 442's ;-)


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[Rocket Power]

And Russ, your pm inbox is full.

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[Russ Jerome]

Oh snap!!