i just built a 350 4 bolt main had the block and crank taken to machine shop had it cleaned honed and new cam bearings and freeze pluck put in. the crank was turned 10/10 put in the same stock pistons back in with new rings (top is molly) put my heads off of my 305 iroc engine that i had rebuilt and ended up throwing a connecting rod. It sounded like i had valves knocking so i figured that maybe there were some bent valves because of the fact that i threw the rod bearing on the motor the came off of. so i took my LT-1 heads to the shop and had manley 202's and 160's machined in i put those on and still valve clatter ive put in a cam from summit racing (sum_1105) new stock pushrods and new sealed power hydrolic lifters. I feel that I have done everything correctly putting it together several times now and still valve clatter. can someone clue me in on why this is happening and what i need to do to fix it?