can anyone tell me if this is right motor?? casting# on block is 10066036. the number on the paper tag is 12499529. i know that this is a target motor with bigger cam, but the motor does not run like 290 horse motor!!!! i think gm sent me a target motor(249hrse) and labeled it a 290 horse motor. how can i tell?? it doesnt lope at all, has 15 in. of vac and wont time right(shows more timing than it runs like,shows alot of timing but u can tell its lugging) takes more timing too run right, and balancer is right on tdc, checked it. any suggestions????? do you think i need too put a adj timing gear because i was told that with this 327 cam (450-460 lift) back in the day that gm had too retard it 30 deg because people would here it run at the dealership and hear it lope and they wouldnt buy because they thought something was wrong with it so gm recalled them and retarded them to take the lope out of it. so is this motor 30deg slow, do i need to put offset cam gear too fix it or did i just get a motor that i cant time because no one can figure it out!! numbers on front pad by the head are imo713-7h04, if that helps at all.