What are you 1-ton guys getting for MPG?

[5Tractorguy]

I think after 8 years I finally licked the engine/trans problems with my 1-ton. Some may remember my brief thread about swapping in a TBI and ECM from a '91 3/4ton Chevy.

Well I did, it runs pretty darn good now but only gets 8 - 8.5mpg. And that's without putting my foot in it and unloaded. (350 and TH400, probably 4:10's. About 2500rpm at 55mph).

I know I shouldn't complain being what it is, but I'm finicky about how stuff runs so curiosity gets the best...

My dad said he used to get about 9mpg with the '91 so I'm assuming at this point it has to do with how the ECM is programmed for the specific truck.