Sorry Dean, I missed that somehow.
I think you will be fine. There are many engines that turn higher RPMs than the average GT40 (Honda S2000, Audi S4S, RX8s, Lotus Exige, Esprit, etc) that I see at tracks frequently. All have AC and will have to have approximately the same pulley ratio as you do to make sure the AC will work in the intended cruise range on the highway. I have never heard of anyone having issues nor have I experienced any problems myself. The clutch will free wheel and won't turn the compressor at all, and the pulley clutch assembly seems to be fine with high RPM.
I remember some years ago looking on the Sanden site or literature and it listed the RPM range for compressor functioning as well as max pulley speed. When I did the calculations for my RF and the pulley set I had there were no issues, free wheeling or engaged.
Ron