Nitrous Nate

I have a 1999 FRC MN6 Corvette. I am getting ready to do a engine swap and was wondering if anyone has removed the a/c compressor with a ASP underdrive crank pulley? What size belt do I need to get? If anyone has done this or know what size belt I need that would be great. Also If anyone has removed a/c frome engine acces. what kind of H.P. gain do you think it will help? I am going to remove the a/c unit from the dash and install a swith panel there, so hope I see a gain from the a/c delete!