Ok, here is what I have done. I drilled into the left side oil passage, through the oil feed to the head, with a .250 drill and cut off oil supply from the cam, by drilling 1/8" in between two holes of the cam bearing, and installed so it lines up with the mains. This was done so mains and rods don't starve, and went with a AN-4 cross over to right side. I also did all the other oil passage mods, including the AN-6 lifter galley mod, with the #1 left main blocked off. It now is feed by the right side. I know from building small block Chevy race engines, with shaft rockers, that full roller rockers use more oil, but they oil though the push rod. I just want to know what size is too big, and I'm not going to debate my decision. That being said, WHAT IS TOO BIG!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!