These guys did an amazing "Top End" for me this winter. For more details, check the "Dyno" Section, Jack. Special thanks men. Estimated power, 809 H.P. @ 6200 RPM, Hi Helix Impeller chart says about 811 [email protected] 6160 RPM. with a "B" cut impeller. !!!!!! I'm ok with that. It turned 6160 with a HI-Helix B cut.