One reason i bought the motor was because the one i had was modified and i drove it to California from AZ going 112 mph half way. It overheated (Didn't blow head gasket) and stripped the studs out of the head. Well i did a helicoil job on the head and i constantly had to keep tightening the bolts it got irritating i'd drive down the highway and itd sound fine then the lawnmower noise i'd kick in. I went through half a dozen manifold gaskets.