So my 1994 GMC k1500 5.7 4l60e with 6395 ECU, running $0D, has had an issue where the chip seems to get corrupted. It's a genuine SST I bought from Moats in 2020, soldered to a memcal. Seems out of no where it will all the sudden go into limp mode, place stock memcal in and it runs on it, check the chip with the file burned to it, and it does not match, so I assume the only thing that would do that could be the alternator? It has a parts store one on it, it charges, but what else could cause this?

It's not used much right now, but I'd like to be able to take it on road trips more reliabily. I have two possibilities for doing that, 1 parts cannon, or replacing the alternator, or 2 soldering a chip in a spare memcal so when it happens I can swap memcals and be on my way. It's done this a few times, but it seems to take a while, it's not an immediate deal. And once I burn the chip it's fine again. When it happened before I thought Maybe it was something to do with the chip adapter, but I have that eliminated now with the chip soldered to the memcal, and it has still done it twice since. It doesn't get a lot of miles on it, mostly a spare truck, but my brother might want to take it out of town for work, and I'd like it to be reliable.

So any ideas, or anyone have anything like this happen before? I haven't read anything like this before.

Also I don't think it's related, but on occasion it will stall while idling, restarts fine, but won't restart unless you key off then back on. Always seems to do it that after it's warmed up. Logs just seem to show it quits running, kinda hard to diagnose, as its intermittent. Ignition switch has been changed a couple years ago .
Truck has fresh tune up cap rotor wires plugs oil change ,new fuel tank pump and lines in 2020, and rebuild the TBI then too. That's all I can think of thanks.