Other than AFM and injectors, I don't know of any differences. The ECU's are marked differently, but I don't know if they are different internally or not... As far as it not priming, I don't think a transmission inhibitor switch would make any difference... they only stop it cranking, right?
Are you sure the fuel pump is good? Sometimes when the brushes are worn, you have to punch them to make them go. I once had a fuel pump go due to bad brushes and the pump I replaced it with had the same problem. And the pump after that, too. I installed a fuel pump override so I didn't need someone operating the key while I punched it. Then I got sick of being stranded miles from home, so installed a bosch pump and the alternator couldn't keep up, and I almost got stranded again. Then I replaced the alt and the new alternator's diodes died.
My name is Jared, and I'm the unluckiest person on Earth. Thanks for listening.