[Ironhorse]

When these trucks were built, gas mileage wasn't a concern with gas prices being in the $0.20 to $0.25 range per gallon. They were built from real steel, very little if any plastic and were meant to haul any and all items. My '71 4x4 came to me with a 350 V8 & 2 BBl carb. Seemed 11.5 per gallon was best it would do, 4 speed and 3:07 gearing. Now it has a 350 with 625 CFM Edelbrock carb and Performer intake, 350Th trans. Haven't checked mileage in a long time but probably does worse now as truck performs better and the foot is heavier, LOL. Your in the ball park with lots of other folks even with the inline 6. As truckster mentioned, that I6 is working to move your truck down the road.