Have you done anything to the front axle? Disk brakes? Changed the bolt pattern? If you're looking to keep the 6 lug pattern, I would keep the stock rear, and either swap in the aftermarket 3.38 gears, or use an overdrive transmission. If you've changed the pattern up front (5 lug disk brake swap), then you'll want a rear to match the bolt pattern. With the Ford/Chrysler 5 x 4.5 bolt pattern, the 8.8 would be a good choice. If using the GM 5 x 4.75, look for a '98-'04 S10 4x4 with the ZR2 off road package. That one has a variant of the '88-'98 full size truck 8.5" rear with the 4.75 pattern, plus disk brakes. It's narrower than the full size truck, but wider than a standard S10.
