Hey guys, I just picked up a nice running 87 f350 4x4. It has a 6.9 with the C6 trans. I am wanting to swap in a e40d from a 1990 f250 4x4 with a 7.3. The truck will mainly be used on the highway driving long distances so I would like OD since it doesnt like to go more than 55 as it is. I have been searching for write ups about this swap but not finding much. I have done swaps before on other trucks. But I am looking for input and suggestions for this one. I know I need the computer and harness from the 90. But can I use my t-case? What about the cross member? Are there any flexplate issues? And any suggestions about getting it wired, especially the od button. Just any advice and suggestion would be appreciated. I hope to do my own write up with pics as this gets underway.

Thanks....

 

I think you will need the E4OD flex-plate off the 1990 truck.

I don't know if it's easy keeping your T-case.


The cross member, if you have access to the E4OD one, take it, or I think you can modify/move the C6 one to fit the E4OD.




Your probably stuck with 4.10's in that truck, and with the C6 will be killer on the highway.

 

I thought I read on here that the t-case are the exact same on those two trucks. The f250 is a new arrival at the jy so i can buy whatever i need but i would like to keep as much as I have to keep the cost down...

My axle code is 39, I think thats full float 10.25 with 3.55's

She will go faster than 55, but that seems to be a sweet spot. The engine sounds good and runs about 2250rpm at that speed. Anything faster seem to sound like its racing the engine. Maybe I'm just used to my 5.0 with OD in the f150.

 

39 is Conventional non-Positraction Differential 3.55

My camper with the C6 has 3.54 and I always cruise at 60 and sounds like it's turning ~2500RPM witch I find it's the sweet spot for my application and I get around 11-12 mpg out of it on a nice road with mild wind.

Anything over 60 however, mpg decreases rather quickly.


If you pick-up is well tuned and you keep it around 60, OD with 3.55 you should see close to 20mpg!

 

i wish it were so easy.
if that was the case,id be pushing the upper teens going 40-45 in OD even with my setup.
i don't see any fuel economy records showing 20mpg averages anywhere for any diesel truck.
i feel you have been misinformed about fuel economy.
MAYBE a feller could push close to this (simply driven empty like a car) out on flat land,no head wind,freshly tuned engine with 3.55's and an E40D trans.but id still want to see the fuel receipts proving it.

if guy claims these kind of fuel economy numbers,then im asking loads of questions and wondering where im going wrong.

anyone hitting close to 20 mpgs (you probably dont need a truck,cus its got to be driven like a car) feel free to show us your true real world records here:
https://www.ford-trucks.com/forums/g...showmpgsummary

1.simply go here;
https://www.ford-trucks.com/forums/garage/
2.under options.select "fill up a vehicle"
3.fill out the form after you run a full tank,and filled it again.

a.fill the tank.
b.reset the odometer (after verifying your speed/miles driven or its worthless.)
c.run the tank low.around an 1/8 is fine.
d.fill up and record the gallons required and the miles driven.
e.do this again at least 5 times in a row.10 back to back tanks if you can.(the more consecutive tanks calculated,the more accurate the results.)

THEN,lets see all those 20 mpg's we've been reading so much about.

 

I never said no one was doing this with a C6. I wrote in my post, with an E4OD with 3.55 should get you CLOSE to 20mpg.

So around 17-18.

Re-read the last part there XLT. lol

 

yeah i just saw the OD oops.
im still skeptical though even with the OD.

17-18 averages as srw,3.55's,stock bed,good engine,mainly long distance traveling,not hauling or towing anything.ok.yeah,probably so.
id still like to see a few records with 10 back to back tanks showing this anyway.i think a turbo might be required to see it happen.

 

We don't know if his truck is a dually or not, it's a 4x4 so most liketly not dually.

Only thing that would hold him back from getting really good mpg is 4x4, hes alot heavier than he could be in a 2wd.

He did say hes gonna be mostly on the highway all the time, so I figured IF well tuned, good driving habits etc. should get him at least 17mpg.



Dreamison, ever taught of a ZF5 5 speed standard? Or in your case, it be to much work to swap since you have access to already all the E4OD related parts?

 

Transfer case, and flex plate can be reused. If you put a billet converter in there, then there might be a clearance issue but a converter with a stock front cover should bolt up without problems.

The cross member must either be relocated to the rear or replaced with the newer one since the E4OD is significantly longer than the C6.

Because of the added length, your drive shafts will BOTH have to be replaced/modified, and the shift rod will need to be lengthened or replaced. However most of the shift linkage (the jumble of shafts and levers near the floor/firewall area) can stay unchanged.

The interior between the 87 and 90 should be the same, so just swap out the interior panel that holds the overdrive cancel button and no one will be able to tell it wasn't OEM. The panel is black regardless of what the custom interior color is.

All of the wiring pertaining to the E4OD MUST be swapped over from the donor truck if you want to run the OEM setup. The computer is expecting chystal clear input from:

barometric sensor (Although this might be only on 92 and up - not positive),
RPM sensor, Vehicle speed sensor,
Throttle position sensor,
brake light switch,
manual lever position sensor (this will come with the transmission, but you will need to wire your backup lights and neutral safety switch into it).

I'm running an aftermarket controller that requires only speed, throttle, and the lever position inputs, - thats it. A newer version of that controller is available, but with the wiring harness it comes to $600 - so if you want to do this swap on the cheap side, you may want to take advantage of the donor truck for all its worth. Assuming you can get that stuff for cheap...

 

Yea the truck is not a dually, not lifted. I drove it about 340 miles so far since i picked it up. And did the full tank of gas and odo reset deal. Driving mostly on the freeway at 55mph unloaded it is getting right at 15mpg with the c6. As far as the donor truck, I can pull whatever i need. They quoted me $350 for the trans, harness and controller. They warranty the trans for 6mos. Are there any write ups on this swap...

 

No writeups that I know of since so few have done the swap. Only one other member came forward briefly a couple years ago with another 86 pickup and he did the swap with factory computer. Most guys avoid automatics and really don't like the E4OD so most of the info you will find is for swapping to the ZF5 speed manual transmission.

I like the E4OD, but they can be trouble if not built or maintained properly (often both offences happen at once).

 

just to play with our minds on economy, my old man used to drive a 67 international, weighed 7000lbs, had a perkins 6cyl and a 5spd OD, 4.11 gears and 19.5" rims (35-36" tire IIRC) and got 23mpg when running at its best. now mind you he drove it like grandpa because it had brakes fit for a honda civic, so i figure it should be possible to get 20 if things are geared and driven right

on my van (E350, 6.9, 3.55s), i've been thinking about getting an overdrive to save fuel, but i'm not too fond of having a computer-controlled box, and its tough to find a clutch pedal setup for a van, making the zf more difficult. currently i tip the scales at 7300-7500 and get about 15mpg with a leaking return line i'm planning to fix....

 

You can put a Gear Vendors OD on the C6.


I just recently got my self every single piece I'd need to convert any 75-91 model Ford van to standard trans., steering column, pedals, engine and trans (RUG 3 speed + OD) shifter, linkages, everything for 50$!



Now if I can find a good ZF5, maybe this summer I'll have an interesting camper muahahaha!

 

Yea I am thinking about the gear vendors set up. I have been watching for a nice used complete one but the price is more than I paid for the truck. 3k new 1500 used for one that will work with my 4x4. I can build a really nice e40d for alot less than that and I have had very good luck with e40d. True they need to be maintained but doesn't everything.

 

My MPGs line up like this with my truck:

24 @ 55
21 @ 70
18 @ 75
15 @ 80

Give or take. Also those are on summer fuel. Most of these days I am between 14 and 16 with a 20' low trailer perminantly attached to the truck with a canopy on the bed and pushing through all weather conditions.

I am a firm believer that anyone with the right gearing behind an IDI will reach 20 MPG if they are not driving crazy and the truck is otherwise not handicapped by extra weight or wind drag.