suggestions better mpg and performance?

[zZackEe]

The engine setup im my truck now just dont feel right, its a late -60s bottom with late -70s heads, an edelbrock manifold and 1404 carb.
Its a almost daily driver truck and the fuel consumtion now is 10mpg and that is to much for me, fuel isn't cheap here (sweden)
now, i have got my hands on 302 heads and i am thinking of getting another camshaft also.
is a 340 cam a good choise?
or this? http://www.summitracing.com/parts/edl-2 ... make/dodge

im looking for a lite more performance (some ponies are missin now) and a better mpg ratio.
i have rods and jets for the carb and i have tryed to adjust it but with no improvements.

[Hobcobble]

Are you trying to improve on 10mpg "city" fuel economy or 10mpg "highway" fuel economy?
John

[WD]

Or is it like my truck, 318/727/3.55 that gets the same (terrible) fuel economy city or highway, empty or so loaded down the receiver hitch is dragging the ground and throwing sparks? 9-11 mpg average, depends on brand of fuel, gets the best readings from Chevron. Mine does have a 2bbl carb, an RV cam and shift kit though...

The aerodynamics of our trucks isn't very good, lots of drag. If I swapped my running gear into my much more aerodynamic 49 Dodge truck, I'd see at least double the fuel economy.

[rockingkay]

9-10 is all I get too. 318, 727, 3.55 with 10.5-31-15 on back. If I drop back to 40 or 45 it will do better, but most of the time I am running 55 to 65 mph or 2500 to 3000 rpm on the tach.

[WD]

LT235/75-15 tops out at an indicated 50/55 mph. And everything was freshly overhauled in late 10/early 11...

I even run true dual exhaust, doesn't help much. Only so much you can do with a stock 2bbl on an iron intake.

[zZackEe]

Thats 10mpg highway.
I run a 318, 727, 3.55 and 10,5-31/15 combo so its the same as you rockingkay, i would really get on my fellow trafficants nerves if im only going 40-45 mph because the speedlimit is 120kmh (76mph) and a 2.1 way (2 lanes in one direction and 1 lane the other way and guardrails to seperate them) :)

This truck was an manual 4speed from the beginning and I swept the tranny this summer and before, with the manual, the fuel consumption was 16-17mpg, now I now that the automatic is heavy to turn around but this heavy?
The engine isn't tip top either, something has happened since it almost stall when driving away from a red light for example and it didn't do that in the beginning whit the auto trans

I'm going to do the head swap (and port), maybe camshaft, carb adjustments and change gear and trying to document with pictures and post the result here because the fight for my fuel money has begun.

[soopernaut]

With the tire size being larger than stock, is the speedometer correct? The speedometer would be reading less than what you are actaully traveling if it has not been corrected. The odometer would also read fewer miles than you are traveling. This could affect your calculations.

[zZackEe]

The speedo isn't reading right but I have done my calculations based on a GPS.

[Stevenow]

Wow, 10mpg is all most of you are getting? That sucks! Once I get mine up and running, I'd love to find ways to improve gas mileage and performance. 2 barrel 318 automatic here. Do headers help? Duals? Electronic Ignition upgrade?

[WD]

In order... not really, marginally, no idea as I run points. It is too little engine for too much drag. If you want to stay small block, swap in a 360, you should see 14 or so on average. Or swap in a fuel infested Magnum small block and all of its inherent headaches. You might see 16 mpg out of it if it has a computer controlled 4 speed slush-o-matic. Or swap in a big block for 12-16 mpg if you keep your foot out of it.

LA 318s are just thirsty. Even the wide block 318 gets better fuel economy. I had a 318/4spd 79 1 ton that got 12 mpg. Swapped in a 440/4spd, same rear axle assembly as it shipped with, and got... 12 mpg. Sweptline aerodynamics leave a lot to be desired, Lifestyle era trucks are even worse.

Guys in the Pilot House club are ecstatic to see 12-14 mpg in 218/230 powered 1/2 tons. The big trucks with 251/265 or larger get 4-8 mpg on average. Even my 1994 2.3L 4 cylinder fuel injected, electronic dual plug ignition, 5 speed with economy gears baby Ranger only gets 21-23, but, it does have just shy of 209K miles on it.

[Roxyflash]

The motor must be really tired I had the same combo and got 14 15 mpg.I guess you need to freshen it up and possibly go to a 323 gear I have a built up 383 with 323 and I keep my foot out of it I can get 15 mpg on the high way with it.

[DavidWymore]

If the transmission doesn't have a lockup torque converter, it allows the engine RPM to be higher when cruising, and autos are also known for being less efficient.

I'm rethinking my planned 318/727 engine combo now...

[beastman]

my 318, though not stock, with 3.91's and an od tranny just pulled 12.2mpg, and thats with a lot of hills and city running. my mpg sucks because of my carb, its a demon 650 mechanical secondaries double pumper, if it didnt run so well i'd probably bolt on an afb and get closer to 14-15

[BW68d100318]

68 D100 318 4spd 3.73 gears edelbrock rpm intake, edelbrock 600 cfm carb changed jets and needles, pertronics electroninc ignition conversion 17mpg average, 22 highway. Toyo 285/70/R17. Yes, the numbers are adjusted and accurate for the not stock tire size.