I bought a intake elbow from someone on CL and when I was looking at his 88 5.0 he had a carb lower intake manifold with just a straight upper running over to the tb. I was wondering if someone actually makes these parts or was it a custom setup.
A good portion of carb intakes with an EFI setup are one-off jobs. Really all you need to make one into an EFI intake is injector bungs welded on (in the correct place, at the correct angle) and a throttle body adapter of some sort. Custom work like that tends to get a bit expensive though, so it's not always the easy way out.