Swapping out a 390 for a 302...worth it? Issues?

[athelas]

My 1972 f250 is a great hauler, but I need a second mortgage to buy the gas. It has the 390 with a C6, 3.54 gears. A neighbor has a 1970 f100 with a running 302 and automatic for sale for cheap, and I'm wondering if it would payoff to do the swap, and what issues I need to think about before I take the plunge. This is a first time deal for me, so any advice is appreciated. I'd really like to be able to use the truck as more of a daily driver if I can get the mpg up significantly. Thanks!

[HIO Silver]

My 1972 f250 is a great hauler, but I need a second mortgage to buy the gas. It has the 390 with a C6, 3.54 gears. A neighbor has a 1970 f100 with a running 302 and automatic for sale for cheap, and I'm wondering if it would payoff to do the swap, and what issues I need to think about before I take the plunge. This is a first time deal for me, so any advice is appreciated. I'd really like to be able to use the truck as more of a daily driver if I can get the mpg up significantly. Thanks!

You'd eke out a few mpg out with a 302 swap. I had a '76 LB with a 302 C4 and 3.00 gears and it managed 17 mpg on the highway and about 12 mpg around town.But it was a total dog hauling and towing.

Personally, I think an F250 with an SBF is a mismatch. Why not just pick up the '70 and use that for a DD?? Maybe even sell the 72 after pirating the good stuff for the 70? I think you'll come out ahead.

[Madman]

If you intend to haul anything, stay with the big block.....torque is a driver for pulling, and the short stroke (and small cubic inches) of a small block just ain't worth it, in my opinion......Always an excuse to buy a F100 to use as a driver

[athelas]

Well, this isn't quite what I expected to hear, but I appreciate it. The f100 is rough, but would make a good project.

[Mancar1]

The cost of the swap IMO is not worth it when going for MPG. I have had the 302 in a 1/2 ton and it was not a gas miser by a long shot.

[68RGR]

Not necessarily the same but I had a 302 in an '83 F150 extended cab. Never again in a truck. It was anemic. I know, I know, SMOG stuff, 2 BBL, low compression, etc. Still, for me, never again. Plus, I suspect you will have those same issues minus the pollution controls. If so, I suspect you will miss that 390 more often than not.

[athelas]

Guys, I'm convinced. I appreciate the input. The 390 stays put!

[BrockGrimes]

I had a 360 and replaced it with a 302/5.0 out of a 94-96 bronco running a carb and it's great.
The 302 has plenty of power and gets reasonable mpg. Yeah I missed the tq but I don't do much hauling and when I do it's a trailer I used to haul my quad on.
Or I'm hauling my boat to go fishing. It's got plenty, if you want to pull up a stump buy a tractor.

[athelas]

Thanks, Brock. That 1970 is still sitting down there, calling my name....