I am getting about 9 mpg with my 360 in my 68 F100.
Could I get better gas mileage from a 352 or a 302?
And, would they use the same mounting brackets?
Thanks.

 

The 352 is the same basic engine block as the 360 so it would bolt right up in it's place. 9mpg sounds worse than I'd expect for a 360 are you sure there's not some other issue? Has it been tuned up, etc?

 

Dittos on Cracker, 360 & 352 are both FEs, big torque good truck engine. 302 small car engine while very popular will get you back & forth but is light weight.

Biggest issue is ero, these 40+ year old trucks are huge brick bats going down the road. 9-10 is very common for these old trucks.



John

 

Every time I see this subject come up I just have to smile. I think back to when these trucks were 10-15 years old and into the 70s series Fs and what they were used for. I and my friends and neighbors were using these trucks for hauling in firewood and certain other heavy tasks. Guess what loaded down with a full load of firewood or running empty the milage was 10 to 12 mpg for most of the Ford trucks running 352s,360s and 390s. It doesnt matter what you do to them you will not effect the gas milage that much without doing extreem modifications. These things are just square bricks going down the road with no areodynamics what so ever. Pulling the V8 and adding a 6 in place may help increase milage somewhat. The best I had was 17mpg running empty in a 66 F250 with a 300 six. All that being said if you are looking for milage you need to think about a newer truck not one of these old brick bats. I agree with John and his description of these old trucks.

MPGs.......We dont need no stinkin MPGs.... just drive them and enjoy the simplicity of the trucks that helped build America.

 

I agree, these trucks are heavy and have the aerodynamics of a brick. You may see some mpg improvement by putting in a 302, but the truck will be underpowered, and really, not worth the hassle, or expense. The best way to increase mpg is to drive like a grandpa (or grandma). There are some things you can do to increase mileage, like adding dual exhaust if it doesn't have it already, or bumping the timing up a few degrees BTDC. making sure your air filter is clean, and not plugged up. Doing a tune up on it, make sure your tires are inflated properly, and the front end is properly aligned. If you absolutely want to replace the engine for one that gets better mpg, get the 300 six. Or even a 240 six if you can find one in decent shape.

Jim

 

what carb/intake are you running? if gas mileage is your goal, you should be using a 2-barrel.

 

Provided your truck is 2wd and you putt it around and drive mellow, you can drop in a smaller engine and improve it. My 300 with a 4 bbl and efi manifolds/exhaust averages 15.4 city and thats with 3:73s and a t18 while cruising around at 45mph.
I'd imagine you could probably get similar with a 302 and the right driving habits. However my engine makes all of its power below 3000rpm and even when I drive it like I mean it I seldom ever go above that so maybe not.

 

I used to get mid teens from a 300 with 4.10s and automatic, 7.5 towing and 12@65 empty from a built 360 with 3.73s and four speed, now 17@75mph with a 7.3 IDI, ZF 5speed, and 3.73s.
Ethanol gas will hurt the mileage a fair bit, you may want to search out ethanol free. Also make sure you don't have any leaks.

 

Here's one of the few phrases that elevates my soul....and I need this kind of input from time to time: "We dont need no stinkin MPGs.... just drive them and enjoy the simplicity of the trucks that helped build America".

Amen to this.!
GOD BLESS AMERICA.....damn!

 

I just pulled a 302/C6 out of our '70 SWB F100. No idea what the rear gears were as the 9" was swapped out for a MN12 IRS. I didn't get anything I would call great out of the 302. I spent $15 to go 60 miles. I guess that put me out in the 15 mpg range if fuel was $4.00 gal. You can adjust from there. I had plenty of go fast with the 302. I do not & have never used this truck for hauling anything other than a$$. If it were me I would move to a 302 with an AOD. Move into gears closer to 3:00. That should get you out around 17/18 mpg.

As to aerodynamics. It is the same basic shape as my '90 4x4. The '90 is a bit softer around the edges. I run a 4.9 EFI with a 5 spd. Has lockouts up front & I can coax 17/18 out of it around town. Just all depends on what you intend on using the truck for. Lowering the truck will also help. The less air you have tumbling around the bottom of the truck the better you will do. I have seen a thread somewhere where the owner was adapting a later model air dam (very slight spoiler looking item) under his bump. Again this helps route air. You have 3 basic ways to improve mileage. Drivetrain, air flow & driving habits.

From a personal perspective. If you want good fuel economy sell the truck and buy something else. These never were designed with fuel economy in mind. I put a 460 in mine. For the most part these old trucks are used for either tough work trucks (economy doesn't matter) or toys (economy doesn't matter). Gotta sacrifice something. Either you get good mileage or you look cool Can't have both.

 

My suggestion for an engine swap would be a later model 5.0 or 5.8L with the factory EFI setup. Should put you in the 12-15 mpg range even with the "brick". I've got a 5.0 in my '95 F-150 & it's pretty decent. Sometimes I wish it had the power of the 5.8 but rarely. Driving habits and gearing will make a huge difference too. Later model EFI engine with an overdrive tranny behind it would make a pretty nice improvement. HOWEVER, when you actually sit down and figure out the increase in MPGs you'll get with a swap + the COST of the actual swap you can buy and awful lot of gas for that 360! I agree that what you're seeing now is on the low side and I'd start checking some of the tuneup items. A swap to electronic ignition will help you out too! Should be able to convert it on the cheap with junkyard parts from a later '70s FE donor (Duraspark ignition setup).

My '71 Crew cab has the 390/ C6 in it, about 8" of lift and 35x 12.5" tires. I haven't even looked at MPG cause it SUCKS. Plans for me are to drop about 4" of lift out of it, go to electronic ignition, drop the tire size to around a 33x 10.5" tire & put my good running Quadrajet carb on it in place of the gas guzzlin' Holley that's on it now. Oh yeah, and replace the missing saddle tank to increase fuel capacity so I can atleast pass up ONE gas station... Hopin' to see some decent improvement out of it.

 

Thanks for the advice guys. I just did a tune-up (with new plugs and wires), and I bought some new tires. I also bought a new fuel pump.
It sure is running better. I filled up the tank, and we'll see how the MPG is now. I do love to drive my truck, and I am going to go to a two barrel, with the original intake manifold. That should make an even bigger
difference in mileage. I appreciate all the input.
By the way, I like "looking cool." Thanks, Dan.

 

My '67 352 3 on the tree managed 15 hyw. I never went over 65, and she sang at 60. I'm very satisfied with that for what it is!

 

My 410 I built for my 70 2wd long bed with 750 holley and headers got 12-13 mpg with bunch more power than the 10-11 mpg 2 barrel 360

 

If you want mpg get a Honda,Kia or similar . These trucks are bricks .
My daily driver is a Kia Optima , yeah i know but i drive 100+ miles a day so 31mpg on average is what i need . on weekends i find any excuse to drive the truck .