I am using the F&B throttle body six pac injection on my 440. http://www.fbthrottlebodies.com/ with FAST EFI controller https://www.fuelairspark.com/efi-components.html

I have been running both these systems for six years with "NO" problems.

Bruce at F&B and Rich from Fastman are both great people to work with. They will answer any of your questions.