AKgts,
I like the 3.55 gears better than the 3.07 for the fact that you are in the power band at all times. Third, forth , and fifth are much more responsive with the gear change. You can get a 3.55 for your 8 3/4 anywhere. If you change the cam, you will definitely want more gear... the power band will most likely move up. As far as cams, RSI & TNT both sell custom cams, and Comp & Crower both sell off the shelf cams. On the headers, I have a set of TNT stepped and they are great... check out their site for the specs on what Roy has to offer. It sounds like a killer project, make sure to post the pics !!!
Later,
Joe