Some reasons for EFI conversions tend to work out better than others.

[MadScientistMat]

Right, a stepper is going to have a connector with four wires (on a Mopar at least; six wire versions exist elsewhere). On the TBI, it's a bit of an oddball that works like a moving throttle stop. On Magnum motors and just about anything else, it will have a cone on the end that slides into an air passage.