[olddog]

Jerking the intake off and plopping a intake and carb on is easy, but what about ignition, fuel delivery, and wiring harness?

Assuming you have a decent EFI system, it should be controlling the ignition timing and fuel pump, too. Perhaps the fan and speedometer, as well. The EFI fuel pump is putting out way too much pressure for a Carb, so that has to be changed. If it is a return type fuel system, you should remove that. Odds are you are going to have to buy a distributor. When you remove the EFI wiring harness, you need to provide for just about everything that it connects to other than the fuel injectors, and sensors.

Then you are going to need to tune the carb and get the timing curve set up for your engine. As stated to do it right, you need to use a wide band O2. Many don't and put up with the stench and leave 50 Hp on the table. Without the dyno you will leave more Hp on the table do to the timing curve not being dialed in.

Not hard to drop a grand on intake, carb, distributor, fuel pump, etc. Then another $500 to get it tuned.

Or

Take the EFI to a good tuner. He more than likely can fix it and tune it right for under a grand.