In the process of tearing an all factory 400 down. I couldnt get the dang oil pump to save my life. Beat it with a BFH and it still wouldnt budge. Finally, took the cover off, took the rotor and drove out the drive, the pump itself finally let go.

72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72. Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.