97cobrada

hey guys im kinda in a bind her im in okinawa on tour in the marine corps and my car is back home in the shop having stuff put on. im having an aftercooler put on but i want to change the pully while there at it. my cobra is stock except for the v2 sq supercharger. what size pully should i get? and in two weeks when i get paid im putting on mac prochamber with produmps is that a pretty good set up. and what kind of gear ratio. i was thinkin 3.73 or 3.90? im trying to get as many ideas for exhaust and gears as posible thanx...