My son and I are in the process of rebuilding a 1970 351 c. We had the block preped by napa's machine shop. Today we were setting the preload on the lifters and while turning the oil pump with my drill we discovered that the oil galley plugs in the rear of the block had a small orifice drilled in them. OK I said this won't work. But now I am wondering were these plugs suppossed to go in the front of the block to lube the timing chain and gears ?? And if so how critical are they ?? You see I have already assembled the front of the engine and really don't want to tear it back down. Anyone out there have any input ??