Thanks for the excellent post John. :)

We didn't get the 'smog head' here, we didn't get the F motors either. I would really like to see what the smog exhaust looks like.

"One more comment is that for those who are trying to build power at low rpms and who do not intend to rev past 5000 rpm ( why ?????? since this is no longer the 1930s ) differences in total head flow may not be as critical since the slower an engine revs the lower the CFM needed. Since I have not tested heads with a cam designed to maximize power in this range I could not tell you what the best port configuration is for that RPM range, however, all of our ported street engines ( and even some of the race engines ) produce significantly more power and torque than stock in this range, usually starting from about 2200.
Essentially we are not giving up anything in the low range as as both torque and HP are significantly higher than a stock B20 over a range of approx. 2000 - 6000 RPM or more."

I agree with this 100% If you haven't got a carefully ported head you're just not in the hunt. A good head adds power, torque & economy. Camshaft A v Camshaft B is mostly over rated. I'd still carefully select & replace a cam while replacing the head, but I would never bother to change from a stock cam to something else if the head was stock.

All my heads have intakes that flow 110cfm@10"H2O with .4375" lift. According to superflow it's enough for 180HP. My meanest race engine did 14.6secs@92mph in a near stock weight 1970 144 with a locked 4.10 diff. My Moroso slide rule says that is takes about 170HP to do that.

My twin SU 'economy' car does 400miles on a tank of juice at 65MPH.