I converted one to efi. It was an enderle hat. The guy bought the car site unseen over the internet. Had no idea it was a mechanical alcohol car.
Made it appear to be true mechanical with injectors inside the hat. Used the steel mechanical injector lines as the feed tubes to the iac motor. I found out that in order to make it drivable as a street car with a decent idle speed, i needed to block off the two outer most throttle blades. Turned out to work pretty nice. A whole lot of fab work to do. Even more than I am used to, and I build damn near everything.
The blades are to darn big to have controllable idle below 1300 rpm as originally built. If you close the blades enough to get a real world idle speed, they flex, suck shut, and bind. My cure was to plate off the outer blades inside the hat. This allows the outer appearance to to maintain the look, yet still have a single blade to deal with for real world drivability. I found out after the fact, that the bds kit does exactly the same thing with blocking the blades.
It’s been years since I did it. I believe the blades were around 4” each, so even one is plenty for a street performance style engine.