Need better gas mileage...
 

...everybody does! I have a 1991 Silverado 3+3 dually, 454, 3-speed with granny. I just bought it from the original owner. He changed the rear gears to tow (goose neck horse trailer). I will be pulling light loads (7x16 enclosed or flatbed) and don't need to be able to pull a house down. What are options easiest to extreme. It is in great shape and expect to keep it. I have an '87 K5 Blazer running gear but like the big block torque. Thanks in advance.

typically big block tq and good millage don't go in the same sentence. but re-gear the diffs and change out the 3 speed transmission for a overdrive transmission.