I've been doing a lot of research in this department and found out the following from a lot of knowledgable speedshops.
The 7.5" rear end, stock, is capable of handling over 400HP no problem, provided you aren't racing it with slicks.
Stock, the rear end can handle even more than that because of not having a T-lok.
The axles will hold up no problem to 400HP, even more.
The gears won't disintegrate as they more than likely will not be the weak link in the whole drivetrain setup, even if they are stock. Your transmission (automatics mostly) could be the weak link in it all.
There are ways around that too as well. You can have a good tranny shop, on the automatics, do some drilling on a pan plate that covers that maze of fluid passages that actually does the shifting for you. I know I don't sound credible here, but I forgot the proper names for the plate and maze unit. This mod will improve shifting points and firm up the shifts as well.
There's a tranny guru over at TCOAA that says he's seen V6 auto trannies hold up to 600HP if you make the right mods to it. Far less money than spending $2700 on a racing tranny.
For the cost of a used 8.8 rear end ($550+ used, $1095 new!), you can "build up" and install a T-lok and gears, drive away, and not be stuck with the 8.8 sitting in the middle of your garage floor waiting to be installed if you aren't the do it yourselfer type.
T-Lok - can be had for $50.
Gears of your choice <$190.
Gear install kit <$80.
Speedo gear $15.
New axle seals for 94-98's $10.
Or for 99+ speedo cal unit $90.
Install can be had for around $200.
Getting both tires to spin and better acceleration, priceless!
