I have an '03, with the 5.8, when towing my boat it gets around 8 mpg. (boat weights around 2000lbs) but it has a high speed rear end in it. It would do better if i lived in Kansas or someplace where it was flat ground everyplace that i went.

I saw a '76 for sale at acar lot the other day and they are asking $3700, here in south central Pennsylvania