So I bought this 1990 f350 4x4 crew cab longbed from a guy for 900 bucks. Sweet truck, its from California so its basically squeaky clean with low miles (besides it got spray painted camouflage...it was previously a black xlt lariat ... and has some electrical issues, all previous owner flaws).

It has 32 bfg a/ts, 4.10s, a 351w and e4od. I tow my mud truck, a 351 ranger (about 4k lbs, with a dual axle trailer im guessing no more than 1500 lbs), to races in NC (where I am stationed) and VA and want some gas mileage on the highway. I am also thinking of lifting it enough to put 37 inch humvee tires on it (you can get them for cheap and they are E rated, better that buying a $1000 set of tires every couple of years). The tires might also even out the mileage I am losing with 4.10s. If my calculations are correct, with 37s, 4.10s are almost like my 32s with 3.55s.

My whole thing with this truck is that I want it to last a while, with the body being so good, I'd like it to last as my tow rig for years to come.

The previous owner put headers on the 351, removed all the emissions (unceremoniously), and messed up the dash (cheap gauges that didn't work, and a lot of butt connected wires, still getting into that mess). At this point it gets about 11.7 maximum on the highway UNLOADED. I have not towed with it long enough to get a fuel mileage amount yet (i don't trust it yet, i really want to kill the PO).

So I'm coming back from deployment and don't want to spend above $4k on the truck (as it was $900 to begin with) but I am trying to get RELIABLE fuel mileage with enough torque to tow what I need (and get a little gas mileage with it).

I am between 3 options...

the cheapest easiest option- converting the 351 to MAF (I already have a A9L harness, just need the e4od controller, which I'll have to buy with other options anyway) with a tow cam (short duration, low rpm) and better intake and mildly port the heads. Also reinstall the EGR... keep the long tubes .

the on-budget option- putting a 460 in it with the previously listed equal accessories (i think gas mileage towing would be less affected). However with this, I will have to get another e4od, the one i have is a reman, its nice, and thats more money. thats the con.

the expensive option- putting a mechanical diesel in it (or PSD if i get lucky). Either a 5.9l Cummins or 7.3/6.9 IDI. I know i can get good tow mileage out of these. However my budget does not allow for it. A respectable Cummins swap I think would cost about 8k (correct me if I wrong). And finding a 7.3 IDI that has not been abused is difficult (also a rebuild for these is pretty expensive, i used to be a Ford Diesel Tech, so I know its not cheap). I would have to get a whole donor truck for this to convert the whole fuel system and electrical also.

I want to know what your educated opinions of my options (also if you want to put the lift option for humvee tires opinion in also go ahead). I am leaning toward the 351w option... I'm thinking I will put a diesel in it when/if I ever come across a dream deal, like a wrecked cummins (or a PSD! ). I'm buying a e4od controller from USShift.com regardless.

don't say sell the truck and buy a diesel... thats not happening.

Thanks guys!

 

Non acrylic finger nail polish remover takes off spray paint without damaging the paint underneath. Just pour some of it on a soft cloth like a sock or a detailing cloth/rag and rub it lightly in a circular motion over the spray painted areas. Make sure to clean or change cloths after you do a patch of it because it'll scuff up the paint.

As for a cummins swap, this ought to help you a bit. Talked to this guy personally and he knows his stuff

Bought a parts truck, tow rig build to follow - Pirate4x4.Com : 4x4 and Off-Road Forum

 

I say follow the path of least resistance which is the 351W. Read up in some Lightning forums there should be ample ideas about your motor and proven combos. There are a lot of factors to consider when you go 37's and all will change the characteristics of the truck especially when towing. The lift will affect steering, driveline angles, drivability. The tires will add rolling resistance, braking, ride. That Windsor will have its work cut out for it. The good news is with a 90 they sit pretty high from the factory so you can get away with less lift to fit 37's. Be sure to check the tires age before you buy. The tire may look new and have full tread but is 5+ years old and can present a danger. I know guys that have bought the oz tires and come to find out one or two were over 8 years old. One did blow out and destroyed the front fender, grille and radiator on my brother in law's superduty. Read up on old tires then asses the risk for yourself. Me I'd go 35's with 4.10. Good luck and post up some pics when you get a chance.

 

Ok.. are you ready for the honest truth? You should have bought a reg cab 2wd F250 with a diesel.. not the biggest/heaviest truck made with the smallest available engine. And.. there is no getting fuel milage while towing with a gas engine.. not gonna happen.


You already have an E4OD controller in the truck.. it's the stock PCM. Putting a MAF PCM on the motor isn't a bad idea but it's not necessary to get more torque and a bit more HP from this motor. Add a Crane 444232 cam and lifter kit, 1.7 rockers and upgraded valve springs, GT40 heads and port the stock lower intake, that will really wake it up. I'm not even gonna talk about the other options because you have already pretty much ruled them out. Do not but a lift and even bigger tires on this truck that will totally kill any potential gains from this motor, and forget about the big block they only get 12-13 mpg at the best of time

 

these would be fuel economy killers.not aids:


..............................


well at least you know what would be your largest gain.

otherwise,if you want to actually improve your economy;
adjust the nut behind the wheel.this is priority #1 or you;'ll fail before you begin.
take off extremely slow and let off the fuel as soon as you know you'll roll to your stops without using anymore to get you there.drive the minimum safe speed you can legally at all times (while in your highest gear without lugging.)
alter the truck a bit for your use;
swap the rear axle with one with 3.55's
install 235/85/16 tires
install a low front bumper valance (preferably to match or 1/4" lower than the lowest part of the trucks underside.)

your budget is 4k.
you bought the wrong truck and for too little.
you bought a 4x4 crew cab gas job with oversize tires and 4.10 low gears.
the truck for you should have been,a 2wd reg cab diesel truck with 3.55's.you can find these all day long for way under your budget.sell and rebuy brother.you'll push 15-20 mpg.with your current truck you might gain an mpg at best after your 4k is gone.

 

Yeah, I just really like the body package. I won't find a diesel that has as good of a frame or body condition as this truck. I'd just like to keep it. Its also always been my dream tow rig, a 4 door longbed, even the bricknose (I love b*st*rd vehicles). I'm looking at some potential donor trucks now, can my sbf e4od 4wd tailshaft work in a diesel 2wd e4od housing to convert it to 4wd? All 4wd diesels are more expensive. If i can get away with buying a 2wd and converting the transmission with already-owned parts, then we are talking more my budget range.

I know the effects of larger tires and lifts. I don't want to buy new tires. I guess I'm just cheap. The nut behind the wheel is pretty obnoxious. I don't want to use 37s. scratch that idea...forget I said it.

I really kinda wanted to do the 351 MAF conversion to see how well it could do. Honestly, I know that it would never have the potential to get gas mileage. I just kinda want to see if it is possible... Maybe for another time, when my budget is larger.

What kind of fuel mileage at most do you think is attainable with the 351w loaded (I think unloaded 15mpg is a reasonable goal). Same for diesel?

Hey thanks guys for being honest. Sometimes biased opinions are needed to see a better side.

 

Here are some pictures of it.

 

If it was me: keep the truck as it is, by time you factor in all the "mods" and their costs the gains would be so minimal it would be a fruitless investment. I'd take the $4k and take care of the electrical grimlins, paint, winch so I could use it to recover the Ranger, and a new set of rims and tires( biga$$) ones keep the white steeliness it has on it with a 265/75/16s and use them for towing and winter thrashing, (fancy rims are for the ladies)

As for fuel economy: the average car payment is $475.00 like most owners here or rigs are long payed for, you can buy a lot of gas for $475a month

 

good idea on forgetting about the 37 inch hummer tires.
they look nice, but are garbage in mud and snow. and they ride like crap.
the only thing going for them is that they are cheap.

 

Converting a 2wd trans to 4wd requires complete disassembly to change the output shaft.

Converting it is most definitely possible just more complicated with that E4OD in there.. you have some custom wiring to do to run a dual PCM setup.

Single digits loaded and low teens unloaded, maybe after you do the upgrades suggested above it'll get into the mid teens at 60mph hwy cruise.

 

Yes. that is true. I don't think you understood my question. Are the SBF e4od internals the same as the Diesel/BBF e4od internals? If so I won't have to source another 4wd E4OD for a diesel if I buy a 2wd diesel truck.

Paying for fuel for two vehicles in one weekend sucks (especially when one takes 93 at the minimum). I want to go check out some other mud racing places in the area is all, they are about 2-3 hours away at most, but while pulling a trailer, every cent counts.

This is the Ranger that I built which is the reason for getting this truck better for towing (sad that my goals are driven by wanting to spend more money on gas in the other truck? naaa...)

 

no. diesel trans is diesel trans only. gas transmissions are not the same as the diesel trans.

 

I'd say 7 or 8 mpg, loaded. 15 mpg empty might be attainable, but 12-13 is more likely.

 

well then... I guess a zf5 swap would be more worth the effort at that point.

Hey thanks again, I'll try to keep updated on what I decide. Looking like a MAF gt40 351 and zf5 swap right now. Conanski made me think of a good point. Why spend money on the controller if I can spend a little extra and make better gains and reliability with a ZF.

 

Yes a ZF swap would make the most sense, the E4OD is also well known for being a power robing pig so the manual should free up more power.