Varied Lifter Bore Oil Holes

toolmanmike said
...You have to get the shavings out of the hole and you can't do that with a 24" bit...

I agree, that's a big problem with a regular twist drill. But a gun-drill has a straight flute and oil passages that force the chips out. http://www.unisig.com/gundrilling-education/what-is-gundrilling.php

Maybe Ma Mopar didn't gun-drill the oil passages, based on all the reports of step-drilled holes. Somehow, it makes sense that they'd do that. #-o