9000 rpm is wayyyyyy to high id say your losing about 20 hp over rev. didnt you say in previous posts this is a d and d race engine you have? if so cant you contact them to find that out?? the 550 a/c eng makes peak power at about 7700/7800 rpms. if your eng is d and d i have no idea what the peak is, are you running pipes? the only way your rpm should be that high is with race pipes and porting that call for it. for example, i've got a set of slp twins coming for my sled and with those plus porting my eng has to run at 8800 vs. 8250 that it is now.