Another update with the electrical on my truck..
I got the Tech II and went in and was able to communicate with everything on the network (all modules, ECU, TCM, FPCM, etc.) I cleared the codes in every module to start fresh then just left the key on for about 10 min to see if any codes were generated and there were none. So I started the truck and it ran for it's normal ~2 min then it shut off again I checked every module and all of them had a code saying that they lost communication with the ECU and the ECU was not commable with the Tech II at all. I waited about 1 min with the key still on and then the ECU came back on the network and was able to talk with it via the Tech II with no problems and it had no new DTC's other than the Crank Position code due to it being a new ECU, so that DTC is expected.
Now here is the kicker since the ECU fried I had a loaner ECU from James that did the same thing as my new one that I bought from the dealer. I do have another loaner here from James that when I put that one in the truck will stay running for more than 2 min but that ECU gives a DTC of P0604: Internal Control RAM Error
So we have checked all of the data links for the high speed bus on the truck and highest about of Ohm's we had was Ω0.4 which next to nothing. So we went looking for devices that would cause the original ECU to get toasted and the current ECU to get knocked offline for ~1 min. so we started with coils. I pulled all 8 coils off of truck and using the ground pin of the 4 pin connector we checked the other three pins and took a reading and all 8 read about the same then we checked where the plug wire plugs in and all 8 were the same then we looked at the coil and the two bolt holes have a metal sleeve in them and we put a probe on one and the other one on the other bolt hole and 6 of the coils read less than Ω0.5 however 2 of them when we put the probes on the bolt holes started at around Ω100 and kept climbing from there. So at this point I'm going to replace those two coils with two new ACDelco coils and test again and see what happens. If that doesn't fix we'll look at injectors since those all came with the supercharger.
Timeline to help keep it all straight:
-September '17: Got the truck back together it ran for 1.5 days and toasted the ECU (P0600)
-Sent the ECU to James he said it was toasted and was going to get remaned
-James sent a loaner and it would start and run but shut off after ~2min. At that time we assumed it might be a Passlock problem.
-Sent the loaner back to James
-Added extra grounds from the fenders to the block & block to frame.
-James got the reman back but it had issues so he sent it back to get redone again.
-He sent another loaner this time but vin was corrupted in it when looking at it in HP Tuners and then found this out: https://www.hptuners.com/forum/showthread.php?28327-E38-E67-Full-flashing-warning
-James sent another loaner ECU/TCM (which I still have) and they truck will run with that loaner but I get DTC P0604: Internal Control RAM Error with that ECU.
-So in the interest of time I just bought a new one from the dealer.
-Sent that one to James and he flashed it and sent it back and was doing what is described above.
-Got the Tech II and found it was dropping off the network with no DTC's as to why and then discovered the potential Coil issue.
So that's where we are at the moment, I'm hoping the coil's are the issue but I'm not holding my breath about it.