when i start my engine up and give it some gas, u can hear this nasty metal hitting metal noise. It sounds like a rocker arm is hitting the vavle cover, but i took the vavle covers off and checked and everything seemed fine. I put new the X303 camcshaft in it, new lifters, roller rockers, push rods, and guide plates. So i'm wondering if it could be a bent valve or what? so if anyone has had this problem or know of someone who has i need ur help? thanks