Could Use Some Help/input

So I bought a 91 LX 5.0 a couple months back. Did regular tune up and cleaning.. Had troubles but most of them got fixed. I am now having trouble with what I believe to either be the TFI module or my msd ignition box. There is currently a Wells tfi on now. When I first noticed a problem was trying to start the car after it was warmed up. I would try try try but it wouldn't turn over. I sit sit sit and get a jump and starts right up, assuming I killed the battery and the TFI cooled off. So I replaced the TFI (with one from LMR) and drive around and car cuts off in middle of the road (pretty embarrassing). Push into a gas station and let sit, and a buddy tells me to hook up stock ignition. Starts right up with no jump. I ordered a "Motorcraft" tfi from rockauto. Same problem except I was able to put the original tfi on right away and stock ignition and fired right up. I'm lost at what to do. Thanks for any help everyone.

These are pics that I got from the rockauto part I purchased.

I also read on here to use the heat sink from radio shack. So I did use that and not dielectric grease..

I just can not figure out if my problem is my msd box, tfi module, or if I have greater problems going on.

Also when I was stuck at the gas station, I walked to auto zone and they let me borrow a voltmeter. They guy said the ground on my plug to the coil from msd box is bad. Could that be the issue?

Ok thank you. I am off of work on Friday I will try this.