Need some real numbers, MPG...

[83GMCK2500]

I have been following a few peoples' build threads and I am looking for some good solid numbers on economy. I'm talking daily driven, mixed, hwy, city, anything. Also, how the truck and engine is configured. I have an '83 4x4 3/4Ton and it will be getting an LQ4 and an NV4500, might even regrear it from 4.10 to 3.73. I am trying to estimate what my economy will be. My intent is to inject it with a 4bbl manifold drilled for injectors, and an air-only throttle body on it. Maybe a mild cam, looking at the SDPC HT1 cam. Specs: HERE Also, LQ9 flat top pistons are a possibility.

I am sure, going from the old carb'd 400sbc to an LS will be a big change and there will be a period of time when the skinny pedal gets a workout, but I am really interested in what kind of economy these engines are getting in our old iron.