Jump to content


Best possible mileage and engine swap

6 replies to this topic

#1 jmacafey


    Where's My Hammer!?!

  • Members
  • Pip
  • 6 posts

Posted 12 July 2005 - 07:42 PM

Rather than by myself a new truck that would cost like 30 grand I am proposing to embark on a small restoration project of what would be my 3rd Bronco. I am wondering if anyone has any ideas on what kind of engine and tranny swap would give me the best possible mileage and drivability. Has anyone had a Bronco into the 20mpg range. It seems feesible with a fuel injected tranny and an AOD tranny. Perhaps I can swap in an entire setup from a modern Ford? Thanks!

#2 jmacafey


    Where's My Hammer!?!

  • Members
  • Pip
  • 6 posts

Posted 12 July 2005 - 07:43 PM

I meant fuel injected engine of course.

#3 Bully Bob

Bully Bob


  • Moderators
  • PipPipPipPipPipPipPipPip
  • 3860 posts
  • Gender:Male
  • Location:Boulder City, Nevada (Las Vegas area)
  • Interests:Going nose-to-grill with GIANT Bulls here in the high desert.
    Hence-forth my given C.B. trail handle;
    "Bully Bob"

    Hot women, 4x4'n, flying homebuilts -- or -- a nice Super Cub !
  • Favorite Bronco Year?:6677

Posted 12 July 2005 - 08:19 PM

The bad news is the dr. train & aerodynamics won't allow any great mileage. :(
What you describe has been done many times over, & provides great dependability.
I think the EB is the closest thing to a "the best of both worlds" as you can get.
You can drive it 70 MPH to a playground or trail & 4by with the best of them.
THe "NEW" Bronco is probably what you're looking for. @-)
---Jeep recovery unit---
1966 "U-13" Roadster...topless, doorless. (with rag top-n-doors)
200 cu.in. I-6 with 250 head.
$30 homemade HEI elect. ignition.
Pwr. steering, Hurst 3-speed floor shifter.
Split headers, dual exhaust, Holley 1 brl.
Stock axles...456's...32's ...Posi rear. 2.5 in. lift.
Full roll-cage, front.
65 gallons of fuel on board..!
70+ MPH cruise---15 MPG
6 EB's (& 11 early Land Cruisers) referbished & sold..



    Bronco Commander

  • Members
  • PipPipPipPipPipPipPip
  • 559 posts
  • Location:Calgary Alberta
  • Interests:EBs, EBs, Boobies... you know, all the important things in life!

Posted 12 July 2005 - 10:37 PM

Hi J,
welcome to the "zone"
Believe it or not, I have a carbed 69 1/2 cab that got around 21mpg highway.
91 5.0 with 635 Edelbrock on a Weiand 180 med rise intake, stock 3 speed and 3.50/3.54 gears.
And I was running 31" tires at the time....
I say got because I haven't re figured mileage with the new lift and 35s...
Soon I will be installing an NV3550 5 speed and eventually 4.10s. I expect that my mileage will get better with those mods as well.
There is plenty of info available on FI swaps into EBs all over the net...
One of my friends is currently working on an Explorer 5.0 into his sons 66 1/2 cab,
it too will have a 5 (or 6) speed od manual trans. They expect to get 24-27 mpg...
Visit the shop here, www.modernmotors.com
Serving Canadians since 1948.

There's a fine line between a hobby and a mental illness...
Running tally...16 over the last 20 years.
2nd owner 68, well used 69, two 73s and a 77 are currently in the stable.

#5 jmacafey


    Where's My Hammer!?!

  • Members
  • Pip
  • 6 posts

Posted 13 July 2005 - 02:00 AM

25-27 mpg would be like a miracle it seems, if they could pull something close to that I would pay money to here how they do it. Still however who knows maybe it could be done. The Bronco may have poor aerodynamics but it is at least a light truck, and like you say if the drivetrain is geared correctly than why shouldnt a modern engine get mileage resembing trucks of today. If you drop the drivetrain and engine from a newer ford into the lighter frame of a Bronco shouldnt it get better mileage. The aerodynamics of the bronco seem somewhat comprable to modern trucks, perhaps it is not a big of a ceiling as you might think. Seems to me that most efi adaptaions into EBs are not exactly attempts for good mileage, just better than the 8-10 you had before. Better attempts could be made for good mileage, not just the I am gonna throw an EFI kit on my ol 302 or 5.0 80s mustang block.

#6 S_bolt19


    Bronco Commander

  • Members
  • PipPipPipPipPipPipPip
  • 933 posts
  • Gender:Male
  • Location:Colorado
  • Interests:Broncos and hockey are my hobbies, though some say obsessions. I also like to hunt, fish & 'wheel when ever possible.

Posted 13 July 2005 - 09:50 PM

I put an 89 mustang EFI system on my original rebuilt 302 block and immediately went from 8-10 city/12-14 hwy to what I am currently getting 14-16 c/18-20 h. I also changed to 4.11 gearing and have an NP 435 tranny. I would think that if you went with the ZF 5-speed trans. that you would get better than what I am getting. I am also running 33" tires.

If you build the engine correctly, as you know, and match trans, gears & tires up correctly, you can attain 20+ highway mileage. I would say your best bet is to start with the 5 or 6 speed and work out both ways from there. You will be spending in the neighborhood of 10K to get 'er done though. Just a forewarning.

72 Daily Driver

- 5.0 EFI - NP435 - BB 9" 4.11 ARB Locked - D44 4.10 ARB Locked - Onboard Air - Front & Rear Disk -
- Yukon Axles - D & C Extreme Rock Bumpers - Hydro-boost - Stone Crusher Steering -

No honey, those were always on there.....

Motorstats.com Your Racing Headquarters

#7 jmacafey


    Where's My Hammer!?!

  • Members
  • Pip
  • 6 posts

Posted 14 July 2005 - 02:49 AM

Well I have a 90 F-250 that I can take anything off that I like. It has a 351 with about 65K on it. I am thinking it may not need a rebuild and I might be able to do some upgrades on the EFI and drop it in my Bronco. I am also thinking there may be some other parts on this rig that may come in handy, we'll see. Does anyone know about the differences in mpg between a 351 and a 302?

Reply to this topic


0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users