How to get the best mileage out of my 92

[cochran63]

My truck is a 92 silverado with 309,000 miles on the origional engine. I would like to rebuild the engine this summer with optimal gas mileage being the goal. I drive this truck daily to keep the miles off of my new truck. The truck is all stock and has had the suspension and brake systems rebuilt in the last year. It has the 350/700r4 combo and 3:42 gears. What would you fellers recomend to consistently get 16-18 mpg.

[Richardman1992]

When you rebuild it, make sure you do the tbi mods which can be found on fsc or gmfs. Also, make sure you have a free flowing exhaust system. Depending on whether or not they smog in oaklahoma, I'd go with long tubes and a 3" y pipe into a good muffler of your choice. Stock air cleaner does the job just fine, bump fuel pressure with an adjustable regulator and add a throttle body spacer.
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[piecesparts]

I used to have a 91 silverado and when I sold it, there was 315,000 miles on the odometer. I had several things that I used to make it run better and still got really decent gas mileage. I had a set of shorty headers and an exhaust that went to a muffler that had dual 2 1/2" outlets. The catalytic converter was non-existant on my truck and was not required in Kansas. I also had a set of 8 MM MSD sparkplug wires to the factory plugs from a distributor that I had a MSD 6AL multi-spark setup on. I wanted to burn every ounce of fuel that I put in my cylinders. I ran a 180 degree T/stat with a hypertech prom in the truck's computer and I also had the belt driven fan removed and an electric fan installed on the radiator. The fan change gained a good mile per gallon, believe it or not. My truck was also a 350/700R4 with a 3.42 rear end gearing. I was averaging a 19 to 20 MPG highway driving mileage and that was with the high mileage engine in the truck. To open up the air intake, I just put a 4" tall K&N 14" diameter air filter on the truck.