So I have been researching what might be causing my oil leak and slow pressure build on start up.

Since the leak is coming from the oil pump cover I am leaning towards the idea that the pump is draining and takes a few seconds to refill and build pressure.

SO I can't remember if I used an o-ring when i installed the pump or not, but I have been reading in some threads that it doesn't use an o-ring.
If it doesn't how do I get it to stop leaking?

I used sealant and a gasket

The problem with the shadek pumps is the body is too small a diameter so instead of getting pinched/sealed by the case halves, there's a big old gap in there where your oil pressure is bleeding back to the sump directly, an internal oil leak, whether or not it is leaking from the cover.

The solution (which I haven't tried) is cutting a notch with a lathe to fit an o-ring on the inside lip, like has been done in this pic of an o-ringed Berg Pump.

great

So should I go back and use one of my original type4 pumps or see if I can get a groove cut into the Schadek?