ECM swapping

[ZeroNthedark]

While I've got about a million questions to ask, I'll try to make my first one as straightforward as possible.

A friend of mine and I have nearly identical trucks- 2005 Petes, CM870, 18 spd, rearend ratios, etc. Both have been "de-mandated" but have kept the VGT. His truck was originally a 565 or so but turned up to 700ish by previous owners. Mine is a 475. These are dump trucks, BTW, in case that helps. His truck seems to shut off at random times, sometimes once or twice a day, sometimes 15 or 20. The place he bought it from has done a bunch of work to it, and have finally said they think it's in the ECM. However, no one around here seems to have one to try out. I'm hoping that putting my computer in his truck for a day or two would not cause irreparable harm? Any ideas or comments would be greatly appreciated. Thank you.