Need engine help

[Fltche]

Here is my situation... I am a highschool student with a gas hog. I have an interest in offroading but not a serious one. (to explain the interest further, I am not interested in rock crawling or serious mudding. but i would like to be able to take this thing off road for hunting or a trip to the mountians just to play around now and again.) I have a 1980 J-10 pickup with the 4.2L 258 inline 6. It is carburated and stock. The carb is a single barrel as far as i know. I need some help in making it more fuel efficent without taking away the offroading capabilities. But currently i am also planning on getting hotter wires, plugs, and distributor coil/distributor. Any advice is greatly apreciated. Pulling the engine out and getting a new one is not an option for my budget at the moment. Thanks for your help.