The hollow from front to back on the ford cranks was supposed to pump
oil thru the engine at 7000rpm and above
The billet cranks we had made for out top fuelers in the early 70s were drilled with interconnecting
oil passages to balance/insure
oil flow to all the bearings
The bearing clearances determine what the oil flow is not the pump and plumbing--the supply just has to be adequet to supply that volume
Jerry