hi great results from my evo 46 nxturns 13,700 on an apc 11/515% morgan omega my OS 46 sf turns 13,400 on an apc 10 1/2 /4-my ASP 46 turns 12.800 on an apc 10 1/2 /4all engines are on a tower expansion chambers-will go to an 11/4 on my evo 46 next-s/b in the 14,000 RPM range LIKE THIS 46 engine a lot !! do not think the evo engines are get ting the recognition they desirve yet-are true ABC construction- ENJOY REGARDS TONY