i built my motor for torque as thats were i beleive your "pulling" power comes from. its a 502 BBC in a 18' rogers with a berk JG pump A/B impeller. this past weekend i GPSed it even though the motor wasnt running as it should. (needs some tuning) i hit 81.3 mph at just below 5k rpm. i say just below because it never hit the 5k telltale needle as it normally does. but i didnt look to see were exactly it was running. i suspect another 300 rpm after the tune. at around 9.5-1 comp and a small cam this motor is built for torque. i was surprized to see the top speed i reached but it proved to me that my theory was correct.