[Ironangel]

What heads do you have, numbers? If your pistons are factory 454 pistons they'll most likely be a flat top with valve reliefs. With that said you kinda need to do what AussieinNC said and call one of the cam manufacturers and let them tell you which cam profile will give you what your heads can flow. They'll supply the cam, lifters, push rods, rockers, springs, and valves that will all play well together with what you already have, a factory 454 truck motor...If your heads are "peanut port" heads they'll make killer stump pullin torque from idle to 5000 rpm and be done, great towing heads. If they're old school closed chamber oval ports they'll flow north of 6000 rpm. If you choose a reasonable lift cam in the .550" to .580" range of lift you should have ample VP clearance and still make lots of low end power out to 5000 rpm...Call some cam company's, I've ran Comp, Lunati, and Clay Smith cams and have no regrets on their products...Mike