64 dart convert to EFI

What are you looking to accomplish? Easier cold weather starts? Better fuel economy, drive ability? And NEW carb will do all three, but efi will give you a pretty much maintenance free motor with excellent manners in all weather. The 2bbl tb kits are good, all in one units that self learn but give few benefits over the cost compared to an NOS carb for your application. The more advanced MPFI units like edelbrocks pro-flow 2-4 will give you flexible ignition profiles too that will help more than just efi alone. Even the DIY stuff (MS3, Motec, etc) is getting expensive nowadays unless you can find an older model used. A dialed in MS2 or even a 1 can still run a motor well. Good luck. Tell us what you end up going with.