[RICK LAKE]

Broadkill1 What tires are you running? What is the first gear ratio on the trans?
As far as an 8.8 rearend, there are some things you can do to make it stronger.
Complete welding of the tubes to the center section if not done.
Better axles (higher spline count) if not already done.
Rear differential support cover to stop walking of caps in rear
Reinforce all mounting brackets on rear tubes.
Drop the ratio to a 3.25 IF the trans ratio in in the 2.80's for 1st gear.
If too much torque is the problem, better tires or advance the camshaft to kill some of the bottom end grunt.
There are a couple of 8.8 rear build ups in HotRod, Car Craft, Hot rodding, 5.0 mustangs and Fast fords. They build for 700hp motors and 1/4 mile runs. How the bearings, perload, backlash, and setup will be how well the rearend holds up and how long.
As for the 9" rearend, some are stronger and some are alot weaker that your 8.8. Moser and Currie are to of the better known places to buy from. Alot has to do with the material thickness and qualitity of the steel. How the tubes are welded to the housing and if done straight or not. The nice thing about a 9" is you can change rearend gears in about 1 hour.
Last thought if money is no problem, go with a quick change rear like Franklin. You will have the best of all worlds. Rick L.