I'm putting in a 550-plus hp 460 in my '87 GT. It will also have a 175hp Fogger. I was wondering how much hp will the stock 8.8 handle? I have rebuilt it with a fresh clutch pack. Is there necessarily a need to upgrade to an aftermarket differential and 31 spline axles?
I would. Stock axles can handle a lot.....but you are going to be putting down A LOT! Some people have been able to put down 500+hp on stock axles for a while...but they eventually break them.
If you are putting that much into your drivetrain, you might as well step up and build up the rear end. A broken axle can cause some nice damage at the track, you don't want to run that risk....in my opinion.