The EFI are pretty big systems to be installing on a sportster. The 4.5 gallon fuel tank on the customs would probably be able to hold all the sh#t that has to go inside of it (such as the fuel pump, fuel level sender, float, fuel filter canister) but I don't think there is room for the throttle body or even the ECM on a sportster these days. It's gonna take some major design changes. IMHO, I doubt there will ever be a sportster with EFI as we now know it. Unless the EFI system starts shrinking in size.