We did efi on the GMC's Onan. Video of start and run here https://www.youtube.com/watch?v=woA-BxJeTIk https://www.youtube.com/watch?v=woA-BxJeTIk
Yamaha and GM bits mixed with Crane and Megasquirt electronics most of it previously used (battle proven) stuff.

I have 20 or so pages on our blog about the setup under Onan efi links. https://wallyandsue.blogspot.com/
Been messing with it for a few years and since we pretty much are stuck at home it got finished. Interesting fuel tune because it runs at 1,800 rpm or off. It's running fixed timing from a battle proven Ford VR crank sensor. I'm using the original carb as a air valve with the choke fixed open and throttle position sensor attached. The governor works exactly like before with the same linkage and valve.