For those of you who didn't see my first thread here is a quick recap; I wanted to swap my '91 Suburban from the 7060 to the 7427 because my transmission needed a rebuild, and I wanted to run the '93+ force motor so that when I executed my planned 8.1 swap the transmission wouldn't need to be messed with.

Since then I have repinned my harness using Daveo91's excellent guide and received a lot of help from dave w. The transmission is installed and all of the connectors are in. When I turn the key to the "on" position, the check engine light rapid blinks. The first thing we tried was a refurbished PCM, then dave sent me a G1/chip to see if it was the MEMCAL. Every combination between the PCMs, G1, and MEMCAL yields the same result.

I checked my wiring for the 3rd time today, and am 99% sure I have it correct. Should I try a 3rd PCM? Is there another possibility I'm missing? I ended up buying a '94 454 since the guy with the 8.1 was taking so long, so I'm fully invested in making this 7427 setup work. Any help or suggestions are greatly appreciated!