theAutomatics

With say, p255 street slicks and a 3.89 gear posi, How much horsepower and torque can a ford 8" rear end handle before it snaps?

Jfsram

Many factor in finding the limit of a rear end.

As you mentioned, torque and street slicks. Definate recipe for disaster if you launch from a high rpm.

In your case I'd say low 13's is approaching danger zone.

Weight is another big factor and that is on your side.

timeformiller44

the housing should be ok...but eventually u might wanna get a better drive shaft and axles