Originally Posted by RAYFIN
Built lots of hot rods and know how to make power BUT now I'm building a really light weight 83 Chevy 1/2 ton 4x4 to use as a shop truck for my upholstery business. I am looking to build it for great gas milage, mostly around town. We need 4wd in Iowa.
I am looking for engine suggestions. I have a stock 350 with ramhorn exhaust and an edelbrock 600 right now. I also have a performer intake and a quadrajet I'm thinking of using. Weight will be about -1000 pounds. TH350 2.56 gears. Part time 4wd with lockouts. Runs great and I got it CHEAP.
LOw budget but if I can get better milage it may pay to make major mods. My 90 efi chevy SUCKS gas.
Sounds like there's an issue with your '90, any TBI I've ever owned got great mileage. Sure you can't make it work? That said, get rid of the Edelbrock carb and put a "good" Q-Jet on a stock iron Q-Jet intake on the '83. Run tall skinny tires and stay conservative on tread design. The more aggressive the tread the worse your mileage will be. Make sure it's well tuned and mechanically sound. Make sure the thermostat is good and run a 195* t-stat. Make sure the fan clutch is working properly, a stuck clutch can make a big dent in MPG's and make sure you don't have any vacuum leaks. Install a vacuum gauge and adjust your driving to maintain the highest possible vacuum readings ( I've found this doesn't apply with EFI ). Once you've done all that just drive it but don't expect great mileage out of it. ESPECIALLY around town. At that point it's very doubtful you'll find any magic bullets that will make any noticeable mileage improvements without spending far more than the truck is worth.
I just went through all that with an '86 Dodge 2WD with a 318, A-727 and 2.94 gears. I went from 7 MPG to 13.8 but spent far more than the truck was worth getting that last 3 MPG. I did pick up another 4.5 MPG after that though.......... I sold the Dodge and bought an '88 Chevy C1500 with a 350 TBI, 700R4 and 2.73 gears.