After a few spirited runs with my 'Cuda's 440 a few years back, it lost oil pressure.

I clicked it off and walked the mile home.

I towed it home and still couldn't get pressure on startup.

I took the distributor and the intermediate shaft out and primed the pump with a cordless drill. It finally "caught" and everything was fine after that.

I must've got air in the pump is all I can figure.

I drove it for quite a while after that and never had the problem again.