How much hp can a 7.5 handle?

[85 B Regal]

Ok, so I'm planning on dropping in a 69-71 olds 350 in my 84 cutlass. The car originally came with a 231 and someone cobbled a roller 307 in there. I plan on basically freshening up a stock motor, probably with a 2 barrel. I have a 2.41 7.5 with G80 limited slip. Can the rear handle the extra horsepower?

 

[-83MONTESS-]

Hard to say. I have a mild 400 small block in mine and I have been beating it for the past 3 years with no issues with the rear end. But I don't have slicks and never hook. The 7.5 is definatley the weak link in that driveline and your driveline is only as strong as the weakest point. Personally I would find an 8.5 from a 442/H-O/GN just to take away the thought of it breaking every time you launch it. You probably could but money into it with new axles and a carrier but that money would be better spent on an 8.5. JMO of course

 

[81Regal]

Its not the horsepower that kills the 7.5, its when the tires and suspension hook up. The 7.5 gets a bad rap but it all depends how hard you beat on it. I've had several and seems like the transmissions go before the axles do for me.

 

[85 B Regal]

Ya I'm not planning on running it hard, I just want a little more fun than my 307 is giving me lol. Like I said, the motor will probably only have a 2 barrel and single exhaust for a while, and the only mods I would make would be maybe a stock qjet and dual exhaust. Basically just looking for the kind of performance you would get out of a stock 1970 base cutlass with a 350. If I was easier to find an 8.5 I wouldn't hesitate but I'm kinda on a budget and they seem to be elusive.

 

[pontiacgp]

in a 7.5 posi the weakest part of the link is the two pinion gears, (the pinion gears in an open carrier have alot more meat on them), the next weak link is the axles. That being said I don't think you will have a problem. I snapped the pinions cause I have a stick and about 380 hp at that time, I popped the clutch to chirp the tires at my friend's shop and the gears went bang

 

[85 B Regal]

So a posi is weaker than an open diff?

 

[pontiacgp]

the two pinion gears are noticeably smaller then what you have in an open carrier. I have to add I did abuse the rear end for a few months before it blew.

 

[jetsetw31]

in a 7.5 posi the weakest part of the link is the two pinion gears, (the pinion gears in an open carrier have alot more meat on them), the next weak link is the axles. That being said I don't think you will have a problem.

X2 on that. Weak pinion gears. The 7.5 can take about 250 hp with a auto trans and last a good long time. 300 up and breakage is inevitable. I drive my car like a p***y for that very reason. I'm saving up for a custom Dana 60. 900 hp won't break it. 8) Of course then my weakest like will be my T5.
T

 

[85olds]

I have stripped the pinion in one and then the ringer in another and final straw was when the auburn possi spring plate broke and chewed the cones. Got a 8.5 in it now for the last 2 years and it is still holding after I replaced the auburn unit with the race one....but it is not all the cars fault...I do drive it like I stole it!!!

!

in a 7.5 posi the weakest part of the link is the two pinion gears, (the pinion gears in an open carrier have alot more meat on them), the next weak link is the axles. That being said I don't think you will have a problem.

X2 on that. Weak pinion gears. The 7.5 can take about 250 hp with a auto trans and last a good long time. 300 up and breakage is inevitable. I drive my car like a p***y for that very reason. I'm saving up for a custom Dana 60. 900 hp won't break it. 8) Of course then my weakest like will be my T5.
T

I also shattered 2 t5 and stripped 3rd gear out of a world class t5....if in the budget get a tremic tko 600 ( I did and it's holding fine). also get a drive made (truck shop).

My car was dinoed at 394 hp and 396 lbs before the super charger was added

 

[85 B Regal]

Ok, I'll keep the 7.5 in there for now and hopefully I'll find an 8.5 by the time I find a 350 lol. Thanks for the help everybody!