Looking at a Howards solid lifter cam, however they only list amc-mopar lifters. I am leery of oil pressure leakage when on the base circle. Am I over thinking things?

I had to have my last 400 block stroker motor lifter bores bushed using one of Bullitt, Ultra Dyne custom ground solid roller camshafts with Comp Cams solid roller lifters for pushrod oiling, I tried a set of Crane solid body solid roller lifters also which had no oil pressure priming it It had 20 lbs. with the Comp lifters All the other 400 block solid roller cams and standard Comp Cams lifters I've used had 75+ lbs. priming

Cab, got you on the rollers. What I was thinking on this one is that this is a flat tappet and with the lash on the base circle that there would be an oil leak at the cup of the lifter. The more I think of it though Chevy solid flat tappet would do the same thing, and they work fine.

The AMC solid lifters aren't a problem in a Mopar block.

It's what I sell over 90% of the time.