Just to update, I hooked up the un modded 7427, added my memcal and turned it on and hooked up tuner pro. I got the correct flash of the check engine light and tunerpro connected just fine. Got proper and correct readings from all the sensors. So the pcm tested good. I did not start the engine, didnt want to risk harming anything (pcm or engine)
Took it back inside and did the resistor mod and now have a spare pcm ready to go incase the worst happens.