83-86 Slant six OIL Pump! Discontinued???

Why not just get the kit and rebuild it? Whatever the "M" number is in Melling, just replace it with a "K" for kit. I have yet to see a scored oil pump housing. The rotors always score. The kits come with new rotors, O rings, gaskets and stock and high pressure springs. I got mine for my 451 for 25 bucks from O Reilly's.