The c30-94 looks like it is in the range you want. At 80k rpm which is 80% of peak and then go 80% of max rpm at 10,500 so a peak rpm without math of a little over 8,000 pulley rpm. So your crank pulley is 6 inches in diameter and your peak engine rpm is a little over 6,000 rpm so you would want a 1.4:1 ratio pulley. So you would want a 4.3 inch pulley for around 8500 rpm. Your boost will be linear to engine rpm. So your peak boost will be at max rpm. Half of that at 3,--- rpm. I did not do any of the proper calculations for this but this should be in the ballpark. I might start with a slightly smaller pulley unless you can get some confirmation on this.