hi guys. i just picked up this truck a few weeks ago and have slowly been going over it.
my truck is a 1968 f250 with the 300 i6 and four speed (three with the granny gear). it has a 4.10 dana 60 rear end with full floating axles.
my goals with this truck is to get the engine back to the point of being super reliable as i have some long miles to put on it in the future. i'll be towing cars, hauling motorcycles, and probably camping out of the back of it sometimes. you know, using it like a truck.
i have a few questions - what are some things i can do to get the most fuel milage out of it possible? is it possible to get a bit more power out of it while increasing/maintaining fuel economy?
would a different rear end ratio work better for me? or maybe a transmission swap?
my short term goals are just to get it running happy and to enjoy it as it is, but the pick-n-pulls around here get a lot of these old fords in and out often enough that i'd like to compile a long term shopping list for when the opportunity comes up.
thanks guys. i've been lurking the forum for a couple weeks now and have already learned a lot. i plan to hold on to this truck forever, so i'm excited to have found a place to get help and direction when i need it!

 

Welcome to FTE.

You're already way ahead of the MPG game with a 300 and 4-speed. Keep 'er tuned, tires aired, and drive 60 mph. These things are aerodynamic barn doors and more speed results in fuel consumption squared!. Meaning, it requires proportionally more fuel to eke out a few more MPH.

Gearing? Generally, 3.50 is a good compromise between daily driving, more spirited launches off the pad, and towing. 3.25 is good with a 1:1 fourth gear since you have a granny gear. Consider a 3.00 if you do not tow or haul heavy loads regularly.... That would give it really long legs.

More power? Work on the exhaust first... Headers, mandrel-bent 2.25-inch dual exhaust tubing, and free flowing mufflers. Then intake and camshaft. For performance, an Offy intake and a small 4 bbl carb... like 390 cfm or 500 cfm. For mileage, the engine would benefit from a two barrel carb compared to a one-barrel choker.

See you at the Pick N Pulls... I hope you're a "Tool Kit" member to get heads up on their specials!

 

Cool rig. I see quite a few at the picknpill by me too. Wish I could have a warehouse to keep all the good stuff.
My 300 does pretty good all around. It got 13mpg in the hiway when I got it(all stock), and now with the mods I've done, it gets 13.5 at about the same speed. Speed does play a bigger role than gearing with these, when looking for mpg. The EFI manifolds and dual exhaust is a good first start. I would say to get a header, but the ones available dont fit so great, unless you spend nearly $400. I'm a mile from Modesto Picknpul, come by and see what has been done with mine(like the ign, and the 130amp alt.). That way you can see what the mods do compared to stock. I would have no problem driving mine across the country, except for the price of gas.
I'd suggest swapping the gears too, those 4.10 have to be screaming on the hiway. Some gearing calculators will help dial in the closest set you'd need. I'm thinking 3.25-3.55.
Another picknpull swap I was going to mention is the 5 speed from a 90s F150, but hauling a car may be a bit too much for it.