Please help as i`m lost. Am working on a Gen 5 454 in a 1962 Chevy station wagon. When the present owner bought the car it had lifter noise at idle and worsened as rpm increased. The previous owner had installed a supposedly new cam, lifters and adjustable rocker arm studs. I tried adjusting the lifters at 1/2, 3/4 and 1 1/2 full turn down. Engine has constant 50# oil pressure at idle. There was no adjustment to made that would silence them. I decided that the lifters were at fault. Ordered a new Comp Cam XE274H-10 cam, (.552/.555 @ .050 230/236 sep. 110) lifters, matching springs, timing chain and stainless roller tip rockers. Got them all installed and still have the same noisy lifters. Theres no valve cover interference. The rocker studs aren`t marked on their sides and the rocker tips contact the valve stem correctly. This is a crate engine with no more than 5k miles. Could someone PLEASE give me some advise and guidance? With good oil pressure and all these new parts, i cannot imagine what the problem might be.