Hey, hey hey, I have been teaching the younger generation for 34 years and you have to create conditions so that they can "discover" things for themselves that others may already know. Anyway this problem comes up a lot on this Forum so all I can say is that there is a big generation gap and maybe it is aggravated by the nature of short terse messages? Anyway I suggest "Boat" take a look at the site on heads where flow values are given:

http://chevyhiperformance.com/techarticles/41598/

Since I last signed off on flatheads with seemingly simpler technology depending mostly on porting and relieving and choice of cam back in the '50s I too had a lot to learn about SBC heads. The sad facts are as mentioned above:

1. gas today is not what it was in 1965 and may get worse!

2. Pb additives are not in the gas and valve seats in old heads will recede using today's gas.

3. heads designed for 283s/327s using good gas are not optimized for more displacement in 350s/383s and poor gas.

Anyway I am a novice with regard to SBC heads but there is a wealth of information on the Internet (some of it advertising hype?) but here you can get some advice based on actual experience which ought to be more valuable (although sometimes these folks don't agree totally and the debate is educational). Anyway we should not discourage Boats. The problem with economic limitations is that you try to get the right combination the first time and that is not easy so experienced advice can save on expensive experiments.

Don Shillady
Retired Scientist/teen rodder