Bought a new Melling oil pump, bench tested it ok, installed it, and spun it, again NO OIL PRESSURE""". Finally after about a half dozen tries over a three day period, it finally started developing pressure to the engine, and is now consistently doing so. Still don't know the why of this whole episode 'cuz an oil pump is not rocket science, but I'll take'em as they come. Thanks for all the input, and I hope this "case is closed"