John,
My best suggestion is to get a PC program called "Desktop Dyno". I know the 2000 version is about $35, and I think there is a later 2003 version, but don't know about the cost.
There's also one called Virtual Engine 2000. You can downlaod a demo of this one that will tell you quite a bit.
Most important thing is to determine what it is you already have got. Then you can try different things in the program.
These will tell you pretty accurately what different cams, heads, intakes, carbs, etc will do.
One more thing, heres a plug for Comp Cams, I am a satisifed customer, they build really nice stuff. Here is a link to one of their dealers
http://www.racenet.net/
Good luck.