I'm not looking for sphincter puckering power with hybrid electric efficiency. I'd be happy with power to keep me firmly planted in my seat, maybe smack a few passengers heads on the rear window while still making 12-13 mpg. Now the particular truck in question is a 77' CC manual, but even if that doesn't happen, most of the trucks I'm looking at are equiped with 360/390's. Also, I did some searching and found plenty of build tips and add ons, but nothing mentioning accual mileage figures. Ofcourse, even a stock 390 would probably be better than what I have now, a clogged 300 behind a slush box that nets 11 mpg

 

You are in the wrong forum buddy!

Just kidding. Sort of. I got 12MPG with my combo. It runs mid 14s on street tires. You can look at my gallery or webpage to see the specs. This is highway mileage. City mileage is probably disgusting.

 

its going to be tricky to get best of both worlds, but it can be done. you want to get a conservative cam, something like the edelbrock performer, a smaller 4 barrel carb, a holley 600 w/ vac sec would be a good choice, a edelbrock performer rpm intake or a stock fe unit, i recommend headers and duals, and a electronic ignition, a msd or mallory units are good. and have a light foot on the gas pedal !!

 

I agree with led sled. I usually get 14 mpg on the highway doing a consistent 70mph (do not check city...cause I rather not know...and who really cares. A gas station at every corner works for me...ha-ha). I have the Edelbrock Performance package (cam, valve springs, manifold, carb, timing chain, and water pump). The carb is the 600cfm #1406...all bolted to my 390FE...and runs in my '76 F-150 4x4 with a 4" lift and 32" tires.

If and when needed this combination does and will put you in your seat. Of course I do not use my truck as a street machine...but if I want too...it is waiting.

I have also added a few other performance parts to help improve the efficiency of the truck. A Griffin Aluminum radiator with a Flex-a-lite dual electric fan setup. An ignition system (includes 8.5mm Jacobs spark plug wires) from Jacobs using the factory dizzy. Helping with the incoming air is a K&N filter and helping with the exiting air is a single 3" FlowMaster exhaust with the Big Block II muffler.

My truck and system seems to work very well for me and my needs. Hope this gives you a little insight to what you are looking for. Good luck with your project.

 

Hrm. Here's what I'd recommend:

Start with a Ford 360. They're a dime a dozen, and perform well. Get a Crane 343971 cam, and do a MILD port job on the heads. Other than that, rebuild as stock. The Crane cam should give you better performance and fuel economy than stock. Of course, get a iron 4-barrel intake, which should be about a quarter a dozen, or if you're feeling like spending money and shedding weight get a Performer RPM. Put a Holley 600cfm vacuum secondary on top of it. And it goes without saying, but I'll say it anyway, get headers and dual exhaust.

If $$$ permits get a 390 crank and rods, and upgrade to a 343901 cam. A Crane 343941 cam can be used for a broader torque curve and greater higher rpm power than the 901, but you'll want to make sure the valvetrain is good and strong.

With the stock cammed 360 with headers, dual exhaust, and a 4-barrel I get 15mpg, and neck snapping low end performance. I like it. Of course, it's out of commission now until I get the new fuel injection system tuned.

 

biz4two added many great extras to help improve the efficentce of the motor. hope we have helped you out in your search . ledsled

 

All -

I've been reading this and other "mild build/efficiency" threads with great interest, as I'm going to be going through the 360 in my '74 highboy sometime in the next few months as part of a basic frame-off (if such a thing exists.) My truck is a '74 F250 4wd, stock 360 2v, NP 435, 4.10 gears.

Looking at the above list of upgrades: cam, intake, carb, ignition & headers - where does the guy or gal with limited $$'s spend his funds? Reliability, mileage and torque are the goals - big HP numbers is not. Is there any point in doing just the cam and headers if you're going to keep the 2v carb? What will you be giving up? Or maybe the question should be which is most important - new carb/intake or headers, and if you can't do the whole package are you better off leaving it stock?

Thanks for the input, this site is a great knowledge base for those of us who are taking on first-time projects like this.

 

I think the key here is:

4bbl carb vs. 2bbl - the 4bbl has smaller barrels than the 2bbl, so for stop-and-go and light take-offs, the 4bbl will get better mileage (more efficient mix as air is moving faster through the venturis) as long as you don't hit the secondaries. At highway speeds, you shouldn't be into the secondaries. A Holley 600 would be perfect.

Cam - a mild cam (current technology) would be better than the stocker (old tech) especially when you get rid of the 12 degrees of retard or whatever with the '72 and up timing sets. A good degreed-in MILD cam would do wonders.

Headers - open up the exhaust, less backpressure slowing down the piston on the exhaust stroke.

Flex-fan (if you don't have overheating problems) - getting rid of the stock heavy fan, the motor won't be wasting gas spinning up that heavy monster. Big difference in throttle response, has to help some.

Ignition - MSD multi-spark can only HELP the situation, for obvious reasons.

As for porting, that's not entirely necessary unless you are going for lots of power. The bump in the exhaust port could be gotten rid of though. Keep the intake ports rough, this will help keep the fuel/air mixed. (Could be wrong on this, anyone want to pick it apart?).

I have a '74 F250 highboy, 435NP, divorced 205NP, 4.10 rear, 33" BFG's. Have a hot 390, 11:1 compression, Holley 750, Edel perf 390, MSD, 180 degree thermostat. I get at least 15MPG on the highway, doing 70MPH. Don't ask me how, it's probably running way too lean and I'm going to toast my nice forged TRW's

 

My 390/supercab gets 12-13mpg on the original build stock engine. With a little care in the buildup you may be able to set your goals a little higher.

 

i think with a conservative build, such as a mild cam, a 600 cfm carb, exhaust upgrade, and a ignition upgrade you should get better gas due to newer technology .

 

Excellent info Really great ideas, and thanks for nailing down some gas mileage figures for me. You can't even begin to realize how anxious I am to jump on one of these! And Ratsmoker, your engine is one to admire, but did leave me really, really, jealous (and broke, if I were to try and build one similar)

 

So what are you gonna build? Keep us in the loop!

 

It left me broke too Franken-truck. It is an expensive hobby! Thanks for the compliment.

 

What to build...What to build... Well, step one is buying a truck Plenty come around every week or so, but very few have really tickled me enough to call and question. The block will be a, hopefully, healthy 390 (up a 360 if I must). No oil burning/consuming, no extreme wear/cracks/seizures (looked all kinds of trucks). Tear it down, inspect, check tollerances. If every thing is good, I will go ahead and replace bearings, rings, ect, for peace of mind. Perform all the oiling mods listed in the F.A.Q . Clean up any casting imperfections in the heads, polish the exhuast. Bolt on goodies would include, as recommend by present company, Headers, Edelbrock intake with a Holley 600 cfm carb, mild cam, and a nice ignition system (MSD multi-spark was mentioned). I think that would be everything. Depending on the condition of the original block, I could do this between 1200, and 1500 dollars. Not bad in my book

P.S. How would one convice his parents that this is a good thing?

 

Parents? Simple, I've got ya covered.

1. All my friends are getting vehicles.
2. There's are good newer ones, but I'll settle for this old truck.
3. Insurance is low on an old truck.
4. These old trucks are big slow safe tanks, no room for performance here.
5. Any upgrades necessary are to make it more fuel efficient.
6. Dont you love me?
7. It's much cheaper than any late model car / truck.
8. Dad will have use of it to clean out the garage / back lawn / basement / whatever.
9. I wont have to beg to go places this way.
10. It will make your life easier.
11. I'll have it out of the garage in a month, promise!

The list goes on. If I knew more about your particular situation I could help more.