Guys I need some help with a 304 i have recently built. I am at wits end with this thing. I have a new timing case cover, Crown I believe, new oil pump, new bulltear 626 pump cover, new pickup tube with screen, and new oil pan. My problem is I cant register any pressure from the original sending unit location, I have a manual gauge on the auxilury side of the pump cover, but cant only get about 15 lbs of pressure. When I use a drill and pump primer, it takes quite a bit of power to turn the pump. I have tried everything. Also when I drain the oil it appears to be aerated, like it is cavatating or something. It seems like it is mixing with air somehow. Any help would be greatly appreciated.