HELP - 97 3.7L oil pump won't prime
 

Changed engines with a low mileage crate engine. Had new oil pump. I left the sending unit out and have been dry running the engine to get oil primed to no avail. I've filled the filter and even forced oil into the port where the pressure sending unit goes. Nothing is working. Other forums say to make a tool to spin the oil pump with a drill down the distributor shaft hole. There is no distributor on electronic ignition. I'm about out of ideas but don't want to pull this engine back out. Any help would be greatly appreciated.