Ford just rerated the block to 450hp @6500 rpm. I know alot of A/sedan guys were having problems and bitching to FORD so they lowered it so they dont have to listen to everyone. I guess they are not as strong as thought to be. Sucks cause I just built a motor w/ one and I am near 400hp and turn 6000+rpm all day. I put a main girdle on it so I hope that helps.