HEEEEEAAATTTTT. When installing the pully heat the taperlock and then install to the proper position (so it is aligned with the other pully), then heat it again and put the set bolts into place using red loctite.
I have found that this works every time. Always check the 1/8" bolts at 10 miles, 20 miles, 30 miles, 50 miles and 100 miles. They should be seated well by then. Using heat they should not spin after initial setup and be friends with the shaft from then on out.
PM me if you have any questions, and MTN PERF has always been really good for support. Talk to Darrell if you can, very sharp guy. Heath is always willing to help as well and can be reached on here most of the time.