Just at the completion of my recent oil pump install, I've come to a snag. The engine(6.0) is reassembled with a Melling HP oil pump, stock truck oil pan and appropriate pickup tube. My steps towards initial crank up since reassembly have included installation of correct pick up O-ring from GM service parts center, adding correct amount of oil, disconnecting power to fuel pump to insure it doesn't crank while dry, and spinning the engine over in 5 second intervals, hoping to see oil peeking up through the mechanical OP gauge tube. I'm not seeing any signs of oil pressure or the pump picking anything up from the oil pan. I've seen kits online that inject oil into a pressure port to prime the oil pump but they are rather expensive for a one time use and I don't see sense in spending a few hundred dollars on something I'd only use once in a while. Im not 1,000,000% sure the O'ring is perfectly set and is something I'll check here shortly. Is there anything else I should take note of? Any other tricks that would help prime this pump that don't involve buying a kit? And I should mention, I dont' have any sort of compressed air supply at the location.