[Boog]

Back in the 70's some 454's developed occasional lifter peck. If I recall correctly a factory service bulletin instructed to drill a small hole in a oil galley plug at the front of the motor. Apparently the 73-74 years oil didn't bleed off quick enough in the lifter oil galley and the oil got too hot and thin causing the peck.
My Dad had a 72 Chevy wrecker with a 74 454 that did this is the reason I know of the TSB. We replaced the #1 cylinder lifters twice but the issue returned. We drilled the galley plug on that engine and it took care of the issue.
I don't remember the size of the hole we drilled in it though. It was 1975.
Member Keith Seymore has worked for GM forever and may have more info about it.