100 oil psi oh no!!!!

when i crank my engine over my oil psi reaches 100 then the engine dies then i crank it again and it go's to 40 but with a very rough idle then stabilizes after running for a few minutes, looks like i need to get a new oil pump sux

Sounds like the relief valve is sticking. I had that happen to my 81 Capri 200 engine - the oil filter couldn't hold it in and oil shot past the mating gasket.
Not knowing what it was, I hooked up a mechanical oil pressure gauge and it pegged the gauge over 100 psi!!!!!

flushed out my oil system with marvel mystery oil then did an oil change seems to be running ok now

In the meantime, run a Fram HP1 filter. It will handle a little over 100psi. Just in case it sticks.