Pime Oil?

V8 you have to pull out distributer and oil pump drive rod and install a priming rod on a drill. Then reinstall oil pump drive and distributer and hope to get the timing set right. Not sure how to do a slant six but it is probably similar.

I recommend you just turn over the engine without starting it till you get some oil pressure you doing about the same thing in my opinion maybe better its forcing oil through the motor and not just priming the pump. I'm assuming this is just a old engine not some fresh rebuild.

Edit:
Sorry didn't notice it was posted in the slant 6 section