[bobcowan]

The current holley EFI system is >20 years old. Technology has changed a lot since then. Think about laptops and cell phones. As Tom said, upgrade the ECU, sensors, and harness. Fairly easy to do, and not much more expensive than swapping to a good carb. Seen the price of a Holley 750 lately?

Tuning the new digital systems is fairly easy. 75-80% is done by self-tuning programs built in to the ECU.

There are a lot of people who claim that EFI is not any better (or it's worse) than a standard Holley carb. Maybe in a few very limited circumstances, that might be true. But for overall driving in all situations, the EFI is clearly the winner. Even my 15 yo Harley has EFI. I don't think I'll ever mess with a carb again.