Howard,
Sounds like your turning some good numbers, especially for a 9.2:1 motor. You can certainly be happy with those. What fuel were you running?
I agree the 1HP to 1 cube is always my target too. I know I could exceed this if I wanted to with this engine, but again, built for robustness, not peak performance. I could go up a little more on timing, dial in the mixtures closer, play with the carb linkage some more (as I am not getting full WOT), play with the cam timing, and easiest of all run some high octane fuel. This pull was run with pump gas.
Bottom line is...it really doesn't need more (as you eluded to). I can turn the car sideways with a flick of the throttle. The fun factor is there, with out it being a crazy ride and with out any risk of engine burn up from being tuned too tightly.