I built one a couple of years ago with RPM heads. It wasn't really sensitive to the rpm, have no idea of where it made its power, but we pulled it to over 6000. The heads were homeported, the intake was a Team G with a dominator and run with pump gas. It was in a 3600 lbs car with a powerglide(?, wasn't my idea) and 3.23 gears with 275/60/5 ET Street radials. It run 10.4 in the 1/4 mile.