I drive the 86 GMC with the 366 gas motor and standard trans. I love it. I am not a big traveler, so i don't need a diesel. I also love the simplicity of the old gas motors; block, alternator, carb, distributor... Did i miss anything?
These get about 6mpg. Not ideal for a heavy traveler, but i adore this motor and trans. love shifting down the road, makes the kid in me as happy as a clam.
Good luck!