M Code K frame question...

Hey folks
I am putting a 440 into my 69 barracuda convertible. I am makeing a M code clone. I have the manifolds ,k member, 383 motor mounts . My question is the drivers side motor mount is a modified 383 mount . It bolts to the bosses that the oil pump bolts to . Can I have to drill these out with out screwing my motor, (1970 440) or what year of a motor do I need to find That already has these bosses factory drilled.
I dont want to use schumacker mounts