I don't think there is adequate room for the oilers and a stroker crank. I know my N/A 6.1 based 426 does not have them. It is 4.08 bore, 4.08 stroke, 6.125 rod. A 6.1 DOES have the from factory.
there is room. been there almost 3 yesrs and never been an issue. looks like it just failed and fell out upon inspection. they help a bunch even in a drag engine. very under rated part for sure.
