bdyxfshr69

I currently own a 1977 F150 4x4 4spd. man. with a 460 4bbl that somebody installed from a car. I could be gently cruising in town or dragging a brick mansion down the hywy it's going to get 10 mpg. I had a '79 with a 2bbl 351m that got 13.25-13.33mpg. I need suggestions on how to improve the mpg. Has anybody had experience with this setup but with efi instead of the original 4bbl on it? If I had to drop back down to the 351m for mpg I would be willing to do it, but the 460 makes me all wiggly inside. Anybody who's ever driven one understands what I'm saying.


I forgot to mention I don't want to change the way it feels and drives. The first one I owened myself was a '79 with the 351m. When I got in it the first time I instantly new I was home... this is the one. I would like to get at least that kind of mpg again so this one's more affordable to drive. I'd like to do it with the 460. Does anyone have any suggestions for me? I have a very limited budget, but I'm open to any ideas.
For what ever it's worth, I forgot to mention the oversized tires. Just a little, but noticeable. When my speedo says 65mph. My actual speed is more like 60-62mph.

notsosporty98

Filters, plugs, plug wires, and going to a higher gear ratio. Pretty much all I can think of.. Oh, and a lighter foot lol. Ummm... Pretty sure you're going faster than the speedo says. I got my first speeding ticket the other day because my speedo is set for stock 235 75 15's, and I'm running 33's ( 93f150)

bdyxfshr69

Thanks for the ideas. Though not perfect, it's in pretty good running shape. The few set ups like this I've seen. 10mpg is typical. I was wondering if I could do better with efi? New 460's have better mpg but they have all kinds of fancy wiz bang gremlins in places that frankly I don't want on my truck. Including coasting when I let off the throttle. When I said I drove it with the throttle I also meant braking. I can slow down sufficiently usually just by letting up partially on the throttle. If I put a 351m with efi in it I bet I could get 15-16mpg. I would have 4bbl power which would be great compared to the 2bbl, but not as great as the 460. I was trying to avoid losing the 460.
I don't really know anything about gearing. Wouldn't that change the way the truck "feels"? Would I have the same throttle response/power to the road? I know from all the early '80's cutlass supremes and reagles I've had. That the tall hywy gears helps mpg on steady cruise hywy speeds but kills it at town mileage. The higher avg. mpg helps them sell cars and meet epa standards, but a 2bbl 231 in those heavy cars handled like pigs. I'd hate to have a 460 just to cut the legs off of it, you know? I need an expert. You've been helpful, but do you know where I can find an expert in this area? I'm not even sure where to ask my questions except here with people like yourself.
Is there anybody out there that has a pre'80 f series 4x4 with the 460 4spd that they changed over to efi? I would like to pick your brain as well.
notsosporty98 Those ideas were all great. They kind of remind me of diagnosis instructions on the inside of washers and dryers. They tell you to make sure it's plugged in! I always found that a little insulting. But it is the easiest to check first. Same with plugs and wires. They're easy and often most overlooked. I'm going to stop now. I think this post may have run a bit long. That's what happens when I have too much caffeine. I've been typing for about 2 1/2 episodes of Star Trek reruns now. Good thing I chose the "Quick Post Reply". lol