.030" over D9TE block
E6TE heads ported exhaust side, polished chambers
KB137 pistons (.020" in the hole... STUPID, should have zero decked)
factory rods + crank turned .010"/.010"
Comp XE4x4 262/268 cam
Summit brand double roller installed 4* advanced (which worked out to straight up)
Edelbrock Performer instake
Holley 750 double pumper... I want to say 72/82 jetting but I might be off a bit on what it worked out to be, primary is as lean as it'll take without surging
Duraspark II ignition, 10* initial, factory curve
Flowtech 12560 headers, 1.75" primary into 3" collector

IIRC static compression is 9.7:1 and I forget what dynamic is but it's probably around 8.5:1. I can run numbers if you need it. It burns 93 octane and is on the edge for towing on pump gas.

To sum it up the difference between my truck and all the sub-10 MPG trucks is compression and port velocity, and probably overdrive as well. Throw it all together and it gets you from 7 MPG to 12.5 MPG pretty quick. If I was to do an outright tune for MPG I bet she has another .5-1 MPG in her. Zero decking and maybe some Singh grooves would allow for more timing. I think I outlined a similar MPG build in another thread you started a while back. The key is compression, port velocity, timing and lean jetting.

 

So you think that if I port of have the exhaust side ported, with dual exhausts with free flowing mufflers and a 5speed I should be in the 10 mpg range as the PO was getting stock 10-12 mpgs?

 

Combined with the rest, easily. These things all work together. You'll obviously need headers to see the benefit from porting. Timing chain and cam as well to take advantage of it. You won't be able to take advantage of more cam unless you up the compression. It all works together. If you just do some parts you may get improvements but are likely to be disappointed as you won't see major improvements. Worst case is you end up with an all around dog that sucks gas and can't get out of its own way.

Are you doing a new build or what?

 

Its the stock motor with damn impressive compression. No oil waste or anything bad really. I outlined my build in my 2011 build thread. Its gonna have new paint, lift, flatbed, black interior, 35 inch tires, flat bed, winch bumper, 2 small subs new speakers stereo, cab lights, bunch of kcs, winch.

Then down the road a 5speed swap lsd in the rear.

I bought it from the Original owner so he took dang good care of it and I got lucky. Almost 0 rust.

 

80 F350 429(L&L headers, holly 750, rv cam) c6 4x4 reg cab 4:10 35" swampers 10mpg

96 F350 460(STOCK) 5spd 4x4 crewcab 3:55 33" tires 13mpg

Both of these are highway numbers at their highest point

 

Just checked unloaded mileage = 9. Gas prices just jumped $.10

 

We were talking about engines. The rest of the truck isn't relevant beyond transmissions, gears, tire size, weight. Link to your engine build thread?

 

Lol I know I haven't done anything to the motor year. I just like talking about my truck and what it will ideally have. I am going to pattern it after yours though.

 

i have an 83 f-250 4:10 gearing 2wd stock everything including smog pump i get around 11mpg but thats grandpa driving havent had the truck above 60, my old 85 with the straight 6 with 3:73 gearing got 15mpg but i had 35,s and a heavy right foot

 

I highly doubt that with out overdrive

 

Thats not entirely wrong from what I have read. For people who can tune the 4180s they are dang impressive carbs. Although, it was largely the reason of this thread to discuss if it was possible to hit that range and it does appear so.

 

Among all the replies no one Other Than Cadunkle, no one is getting above 10mpg and he has an OVERDRIVE

 

ok i know im getting 11 right now and i havent even done fine tunning yet so i mean its possible

 

Right I know that. I'm just saying that with a properly tuned 4180 these things can actually be pretty good, especially so if they are combined with the right gearing and trans setup. My ideal goal would be 15, however if I do mods and hit the ten mpg mark I would be very happy.

 

My 89 F-250 (4x4, 4:10 gear ratio, ZF 5-speed, 2" suspension lift on 32" tires) got exactly 8mpg if it were empty or fully loaded to max capacity. Unless I was driving it super-carefully like a little old lady... Then it got 7. This is both city AND highway. There was no difference between the two on this beast.

Was kind of nice that it got such consistent mileage, as I could literally watch my trip odometer instead of my fuel gauge and know when to fill up again. I miss that truck, should have never sold it.