@wes beem I think maybe you just got a dud motor if you didn't get to hear it run in the vehicle it came from. I now believe you are right that it's stopped up somewhere between the filter and top end. Maybe you can find a Magnum motor you can hear run, swap it over to a carb and drop it in.
Pretty sure he said it ran good, but had low oil pressure so he changed the pump, is it possible a partial blockage was causing the low oil pressure and got kicked in to a full blockage by the new pump? Fwtw that's my guess
