I am looking at crate motors for my 68 SS. How much horsepower and engine torque can a stock 12 bolt rear end handle?

Welcome to the site.

Well I have abused my 12bolt enough over the years and I have run over 630+ HP through it without any problems to speak of. Now, in the real world of things, (considering that I have been in the differential business for 10+ plus years) I myself would not recommend much over that in a street car.

It really comes down to how hard you are on the chassis and how you drive that will determine its ultimate durability. Meaning, I can give two people the same product and one of them will kill it.......some how.

Maybe you can tell us more about what you are trying to accomplish so that we can give you a better idea of what to consider concerning your differential.

If the car is set up right and there is no wheel hop it can handle a lot of power. Wheel hop can kill the best rear end in a hurry.

Thanks for the responses! This car is primarily a street car and I may take it to the strip on occasion to see what see will do. I plan on leaving stock wheel tubs rear end width. I plan on getting a set of drag radials so I can hook up a little better. The crate motor I had in mind produces 540 HP and 575 in torque. I am planning on bolting up a Tremec TKO 600 5 speed. I have multi-leaf springs, any suggestions on how to control wheel hop?

Change the springs or look into a set of Cal-Trac's (http://www.calvertracing.com/)

Are the Cal-Tracs better that Competition Engineering Slide-A-Link Traction Bars? Will either of these effect how the car rides on the street significantly?

Don't forget to replace the stock axles, they are the weakest link!! I busted one many years ago with a stout 327, never dynoed it but it was good enough for 11.9's in a 3000lb car. I was running 4.56 gears and big slicks. (27"x10"???)

No wheel hop, just twisted the left axle in half out at the flange and the wheel fell off on the starting line!! :eek: I got yelled at by the track's starter for having stock axles. He asked "what if that had busted on the big end of the strip?". Guess I might not be writing this if it had!! :D

Paul D.