Great minds think alike, PonyRider! The head does not need modifications. The Holley EFI is a throttle body with two or four butterflies. It looks like the base of a carburettor and also has the throttle linkage. The control unit is built into that. A couple of injectors sit above the butterflies. It bolts onto normal manifolds. Unless utilising ignition control, it has a minimal number of wires to connect. They supply an oxygen sensor that mounts into the exhaust collector without needing welding. It has a control pad with a wizard to set it up for your motor. After starting, it self-tunes. It is a very enticing idea to contemplate after the car is licensed and running. Extra smoothness, easy starting and less smell.