Miles per gallon?

[Ranchero50]

'71 F-250 2wd with 4 sp and 4.11's was constant 10 mpg combined. Cummin's, 3.50 rear and 47rh OD trans in a '70 F-350 dually is 17+.

[Bvh56]

68 f250 with headers, cast intake manifold new 2 barrel 350 cfm Holley tuned to 14.7 AFR using a O2 gauge, running a 2.46 rear ratio. I'm guessing it's around15mpg. I can't give an exact number because the speedo is off big time.but the truck seems to sip the gas. Oh and it will cruise at 72 MPH AT 2,000 RPM.

[Madman]

I always figured if you owned one of these (especially an F250 4x4) you never really worried about gas mileage!

[Brokenarrow]

Junk the 360. Find a 390 out of a '67-'69 galaxy.(Higher compression than a truck FE, Much stronger engine) Freshen it up, Put it in your truck along with the 2.75 pumpkin out of the car. Put a good quadrajet on it, recurve the distributor and set the timing right (not to Ford spec) Proper timing makes a big difference. Then don't tell anyone what kind of mileage you get, they will call you a liar.

[tqwrench]

Brokenarrow's got a point on the Q-jet. Rochester Qudradajets were an engineering masterpiece in their day. If you can drive one only on the primaries you'll get great economy. The minute you step into those secondaries it will be like flushing a toilet. I had a 70 Fleetwood with a 10:1 compression 472 and if I kept my foot out of those secondaries I could shag 17 MPG out of that land yacht doing the speed limit.

[kato_pup_dog1977]

I built the 390 that's in my 67 f100. Bored .060 over, ported by me, old Holley street dominator intake ported under the carb and intake matched, hedman headers and just over 9.25:1 with an old Holley 830 on top. As long as i can stay out of the throttle the old truck gets 14 in the city on non ethanol super and near 20 freeway rolling 70mph. Truck has its original 4spd and a 3.50 geared 9inch out of a 76. It's not lowered at all. A properly built and tuned fe can get very reasonable mileage. Do NOT tune to fords specs on these motors. I run mine a touch lean at idle with the secondaries a little fat. When adjusting the timing i run as much advance as i can get without pinging at wide open throttle. The MSD billet dizzy is set to 14degrees initial and another 30 advance all in by 3500 rpm. Yep, that's a full 44 degrees by 3500 rpm and no ping! Motor seems to love it.

[HIO Silver]

My lowered "70 LB 2wd is finally out of dry dock. It's got a 360, EFI, a five-speed and 3.50 rear gears. I'm still working out a brake issue so the MPG test loop is still pending. Can it eke out 20 MPG? We'll find out soon!

The second test will be to add an air dam to see if it makes any difference. The final test will be to slick up the aero by taping up all the extraneous openings, body gaps, and excess grill area. Stay tuned and I'll report back.

[Brokenarrow]

You'll never get that kind of mileage from a 360 with stock pistons.(No quench)

[farmallmta]

Brokenarrow's got a point on the Q-jet. Rochester Qudradajets were an engineering masterpiece in their day. If you can drive one only on the primaries you'll get great economy. The minute you step into those secondaries it will be like flushing a toilet. I had a 70 Fleetwood with a 10:1 compression 472 and if I kept my foot out of those secondaries I could shag 17 MPG out of that land yacht doing the speed limit.

Here's how to solve the toilet flush from the huge secondaries: use a Dualjet instead. Looks externally just like the Q-Jet, but the back bores do nothing. I had an '84 Dodge D250 318 with a 360 police Q-jet manifold and Q-Jet carb on it. I put a Dualjet in its place and mileage went from 13-14 to 18-19. And power (torque) increased. But I wasn't racing, just hauling half the world in that truck. Still doing duty on the ranch and just won't quit.

Rochester Dualjet is the answer for mileage and torque, not the Q-Jet.

[Sedvillian]

Just a thought.... Are you using your odometer to compute your MPG's? If your speedo is off and MOST of our bumps are, your actual MPG will not be correct. Use a GPS or Mapqwest to get your actual mileage. Using my odometer, my 70 F250CC with a 390, Edelbrock 600, C6, and 410 gears got just over 10 MPG on the highway, with the GPS it gets 14+ MPG. Which is better than my 71 half ton with a 302, Holley 600, C6 and 325 gears.

[tripped38]

My 72 short bed with a 390 and c6 gets around 12.5. I've never checked the gear ratio in it and it does have an edelbrok 750 cfm carb. Truck must have a numerically low gear in it because it is a dog out of the hole but wants to run 75 all day. I've checked it on a few different loops.

[crazyhorse]

My 72 Ranger XLT short bed gets 15 to 15.4 (if I stay under 55 mph) with a 429, c6, Edelbrock 4v & aluminum intake, Motorcraft spark plugs, MSD distributer, wires , box, Black Magic electric fan, 160* thermostat, headers, 3" dual exhaust, 275/60R17 tires, and the best I recall 3.25 gear.
My speedometer is about 5 mph slow at 50 mph.

[eggman918]

In my 8,000# empty '68 F-250 4x4 Crewcab with a 390 built to ~'69 GT specs with the NP435 and 4.10 gears/31" tires it got 9-10 up hill, down hill, empty or loaded it was a work horse.............but a hungry one
Now with the 4BT it gets 18-20 doing the same job It still floors me that a 250" diesel engine can out work 390" gas engine on 1/2 the fuel when properly tuned and geared for the truck and application.

[rollercam1]

Junk the 360. Find a 390 out of a '67-'69 galaxy.(Higher compression than a truck FE, Much stronger engine) Freshen it up, Put it in your truck along with the 2.75 pumpkin out of the car. Put a good quadrajet on it, recurve the distributor and set the timing right (not to Ford spec) Proper timing makes a big difference. Then don't tell anyone what kind of mileage you get, they will call you a liar.

My dad had almost the same set up, except for the 428 instead of the 390. We drove from Idaho Falls, Idaho to Gillette Wyoming and averaged 18mpg cruising along at 60mph