I know that the 7.5 10 bolt rears are said to be not to strong
compared to the 8.5 10 bolt rears.
The car is a
1987 cutlass salon with a 307 now but in the future the most power i would put is a 350 sbc possible 350hp the tops
i would like to keep my factory 7.5 10 bolt and put 3:73 gears with a limited or posi unit.
My question is
whats the horsepower that rear can handle?
Been looking for a 8.5 but unsuccseful

 

if you are street bound you will be fine with the 7.5 as long as you rebuild it ...
tighten that old rear back up to spec and it will do what you need it to do. if YOU ARE GOING TO TRACK IT SOME WITH SLICK YOU MIGHT want to increase the axle shafts to 28 spline when you do the posi as the posi will cost the same for a 26 (stock G body ) or 28 spline 1990-2004 7.625 cars and light truck units.

Ifr you want the rear to hold USE aftermarket parts..NEW do not use stock old used parts...you will be doomed.

Good luck and when your ready ask for prices we get deals on alot of rear diff stuff and may be able to help.

Jim
JD

 

What Monzaz said X2

If you want to add a little more support, put a girdle on it.

 

Back when I had my Malibu with a mild SBC I broke mine with my first launch on itty bitty 26 x 8.5 slicks. Also any 93-02 Fbody I know that starts racing breaks them. I would not waste my time with one that will ever see track time.

 

I wouldn't bother building a 7.5 at all.

Save your money for buying a 8.5, I know they are hard to find for a G body.

I'm putting a girdle on mine, until I buy a 8.5. It's the ONLY money I'm putting into the 7.5, and I can sell back the cover on eBay

 

Almost all rears fail in the SPIDER GEAR or stock axle areas.
Girdle covers are great BUT really your axles and spiders will fail first before your bearing caps budge.

We do 10.90 with a 8.5 rear full spooled NO girdle cover and the 8.5 and 7.5 bearing caps are the SAME size.

To max out the strength in any 7.5-
-Eliminate the spider gears OR you need to buy the best carrier you can true trac or eaton will be the best choice.
-Next if you can afford to upgrade your axle shaft to aftermarket 28 spline DO IT! (stock 7.5 g-body axles are SMALL 26 spline)
Aftermarket gears will be the final improvement. Again GM gears are basic metal for the A-B car and made to be quiet - they are strong but the aftermarket mix of metal is just plain stronger.
-Finally BEARings after even 20-30 years even if the bearing LOOK good replace them...If you are NOT replacing them you had better be sure your carrier preload must be spot on NO slop for the carrier to shift- If you remove the bearing caps, remove the axles and the carrier is able to be just pulled out of the housing cavity by hand you do NOT have enough carrier bearing preload .

If you pay attention to these 4 things with any rear - MOST rears will hold up well (of course setting the ring and pinion up correctly is a gimme)

Gearheads78 with the slicks. - Does not matter what SIZE your slicks are ...THEY WILL STICK. lol. 7.5 and slicks, high stall and sticky track is a disaster... as you know now.
We use the same size slicks and do 10.90 1/4 mile with 1.39 60 foot...
Slicks are just plain better than drag radials. NO compromise, just stick and go OR BREAK in you case. =:0 Ouch...