Will a bigger crank pulley make a difference? Maybe not so much slippage on the supercharger pulley?

 

I bigger crank pulley would definately help.

The problem with that is all the rest of the accessories would be over driven and need bigger pulleys to compensate.

It would be best if the blower wasn't driven off the stock belt at all.

 

Maximumrebel1, I am slowly going to start a truck that would be similar. '92 rcsb, step side, 6.0, #317 6.0 heads, forged internals, 8.5:1, head studs, custom grind cam, good fuel system, TH-400, 3500 stall,
GT-67 STS turbo 14psi, side mount intercooler, going to try and make the 10 bolt last. It will be a while, but hopefully within 6 mo. to a year.