Performer Rpm Heads

i have a sbc 350 that I'm rebuilding, the heads i can order have either a 64cc chamber or a 70cc chamber. Whats the difference in performance? Or combustion? It is going to be about 20% street- and 80% race. The engine is from a 1969 truck. And I'm not to sure about the emmissions either? I'm trying to build it up to be around 600-650 hp, with NOS. Also I need to find someplace where I can buy piston rods to handle that much hp. The best ones I've found only handle 500hp. The rpm range is 1500-6500. With a 2500 stall converter.

I have added some specs. to my original question. To better help any response.

THX for letting me know about that, I think I'll check out the 40th and van buren area. If I can't find those trailers, I'll see about registering it in Coconino county, in Flagstaff. Does any one have, or have heard anything about the edelbrock e-tec heads?