New to me Barracuda with Mopar Crate 390hp low oil pressure

Just saw this. I am doubtful. There are several restrictions in the system before you ever get to the rockers that control the flow, and these restrictions do not change with the rocker type. Now, if grooved cam bearings were used, then that changes the oil flow game up at the rocker area.
I should have said - roller lifters - I agree roller rockers would make no difference.