Hi , I'm new to this forum. I have a 90 V2500 that I have basically made new. Crate motor, new 14 bolt FF rear, a/c , paint, the norm. The big problem is mpg! I get about 10-11 it has 3.73 rear and a th400 trans. I know the trans is the main problem with the mpg. It you put the truck in neutral it flies down a hill put it in gear and you don't need the brakes. I have access to an 88 suburban with a th700r and though about converting it to that tranny but wasn't sure if my mpg will go up. Or selling it and getting newer one. If any one has any suggestions that would be great! I have alot of money in this truck but the mpg stinks. Thanks for your help!