How do we know there's no gain in performance or fuel mileage? Seems like losing the choke and being able to program the timing advance curve would be big fuel savers, right out of the gate. Also taking improved fuel atomization at all temperatures into account along with more precise acceleration enrichment and closed loop fuel mixture control, I don't see why you wouldn't gain a couple miles a gallon. Not gonna sit here and say that you'd automagically get to 22mpg with the EFI, but a couple MPG with greatly improved drivability would be very doable.

1965 C60 school bus | 1967 GMC 6500 school bus