John,
Your car can fit into several classes, with several engines and 3-4 years (69,70,71,72, and 68 if no one looks too close
). From a 6 cylinder, to a 2 barrel 307 V8, to an aluminum head 396/375. You really need to pick an engine, transmission, and year for your combination, then pick a guy to either build the engine, or at least supply you with parts and technical assistance, as well as machine work. I could tell you about cams, or send you to the guy who does mine, but if that isn't what the guy you pick to do your work does, it won't help you much.
There are some combinations that you can go with that will be pretty quick, for example a 69/70 350/300 stick, or 69 396/375 iron head stick. There are some quick 69 350/255 automatic cars, and that makes a good stick car as well. The 70 402/375 stick isn't bad, either. It depends a lot on how fast you want to go, and how much you have to spend.