Swapping out a 6.9 for a 4.9EFI

nic55kel

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Seriously considering removing the 6.9 from my 86 supercab and installing 4.9 EFI with an E4OD from a 1996 F150.
Possibly the wrong forum if I expect much encouragement.
The 6.9 has a C6 behind it with a GV overdrive attached. It all works fairly well but I am getting rather tired of the noise and the smoke and it really hates the cold which it is here a large part of the year. I don't expect much difference in performance with the 4.9.
If I go ahead with the swap I could have quite a large amount of IDI parts to either scrap or sell.
Just testing the water here.
Thanks.
 

Thewespaul

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It’s a lot of work especially for putting an e40d into an older chassis. What issues is the 6.9 having?
 

IDIBRONCO

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I can understand the cold issues. On the other hand, I'm no fan of a 300 6/4.9 in any way, shape, or form. I do know that there's some people out there who practically worship them though. I wouldn't want to do the swap myself. I wouldn't want to have to swap all of the electrical system over. That seems like a HUGE headache to me.
 

Clb

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Buy a dentside with the 300
Sell the idi and dump the money into it.
 

nic55kel

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Thanks to all who responded. I posted this as a sanity check, obviously not looking for agreement.
I agree it would be quite a lot of work, but doing it for fun with no time constraints.
I do have a complete 1996 truck, it was from an estate sale, only has 85000 miles on it and it appears to have been babied, fresh fluids etc., however it has terminal rust.
Problem is I love the 86 extended cab body style, the one I have is in very good shape and not something you see often here, but would be surprised if it sold for more than $2000 as is.
Most of the older stuff here is very rusty.
The 6.9 has a quite loud knock when cold, I suspect it is piston slap but could be gear train. Anyone who is familiar with the old iron duke 2.5 will know that sound.
If I am going to the trouble of pulling the engine, that would seem the obvious time to do the swap.
I would be much happier with a quieter truck that ran well at -30.
Other than the electrical doesn't seem too involved. The motor mounts and perches should transfer.
Will have to modify or fab transmission cross member and find/fab correct length driveshaft. Then it is just fuel pumps, plumbing and linkages
Wes curious about problems putting an E4OD in an older body style. As I understand it the frames are the same from 80 - 96.
I realize that there is no mechanical speedo drive and I will need a d/s speed sensor with the correct pulse count.
I am currently driving a 2007 6.0 4x4 F250 which is a great truck but costs more than twice the 86 to insure.
There is a demand for that truck as it has a tommy gate, low mileage and is a super tow vehicle, but it is way more truck than I need.
Thanks again for your replies.
 

Clb

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Rust belt issues prevail...
If I had to do this( read HAD TO)
I would buy a doner truck park em side by side and pull the dash/engine harness FIRST.
This will suck the most and be the bellweather of you getting it swapped to a gasser.
When I was young I swapped the interior color on a set of first gen rx 7's
That took a week.
Last year I swapped my 22r toyota out for a 22re (fullie)
Just gutting the donor truck, and gettin the 9 ish wires out and installed into the carb'd cab took several weeks (3-5???) chipping away at it...
If ya love the rig go fer it.
I hope yer wife is a patient soul.
 

FordGuy100

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Sounds like a lot of work but I don't see why you couldn't do it. Might be able to get some better fuel mileage as well.
 

Thewespaul

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Thanks to all who responded. I posted this as a sanity check, obviously not looking for agreement.
I agree it would be quite a lot of work, but doing it for fun with no time constraints.
I do have a complete 1996 truck, it was from an estate sale, only has 85000 miles on it and it appears to have been babied, fresh fluids etc., however it has terminal rust.
Problem is I love the 86 extended cab body style, the one I have is in very good shape and not something you see often here, but would be surprised if it sold for more than $2000 as is.
Most of the older stuff here is very rusty.
The 6.9 has a quite loud knock when cold, I suspect it is piston slap but could be gear train. Anyone who is familiar with the old iron duke 2.5 will know that sound.
If I am going to the trouble of pulling the engine, that would seem the obvious time to do the swap.
I would be much happier with a quieter truck that ran well at -30.
Other than the electrical doesn't seem too involved. The motor mounts and perches should transfer.
Will have to modify or fab transmission cross member and find/fab correct length driveshaft. Then it is just fuel pumps, plumbing and linkages
Wes curious about problems putting an E4OD in an older body style. As I understand it the frames are the same from 80 - 96.
I realize that there is no mechanical speedo drive and I will need a d/s speed sensor with the correct pulse count.
I am currently driving a 2007 6.0 4x4 F250 which is a great truck but costs more than twice the 86 to insure.
There is a demand for that truck as it has a tommy gate, low mileage and is a super tow vehicle, but it is way more truck than I need.
Thanks again for your replies.

Speed sensor is the easy bit, lots of options for that you could even swap the axle from the newer truck in. The issue I see with swapping the wiring harnesses is the firewall is different between the trucks, and the bulkheads for the wiring is different. Newer uses a combination of round and rectangular bulkheads in the firewall, with the tcm retained in the kickpanel, on the older trucks they just have one small round plug, and very little space in the kickpanel. You would need to be pretty creative with the wiring to get everything to work with your current dash, swapping to the newer dash would be a better option, but then you run into issues with the door panels and wing windows not fitting and you have to either swap the doors or swap the glass, panels and wiring. The best solution for the firewall differences is to either rebuild the newer harnesses and repin it to the existing style bulkhead or cut out that area of the firewall on both trucks and weld the newer firewall into place so that the newer style bulkheads can be used.

Do you have a video of the 6.9 with the piston slap? With it only happening in cold weather sounds like a fuel issue possibly an unhappy injector?
 

nic55kel

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Thanks for your time. Unless I am really missing something I don't see the wiring as much of an issue. Certainly not the bulkhead part.
90% of all the sensor wiring, lighting, a/c, cruise control, heater, w/w, starter, tach is already going through the existing bulkhead connector.
So just use the existing harness and modify as required. I doubt if I need even 10 more wires (data link, speedo, brake switch, MIL & ? ). Those few more wires can go through the opening where the speedo cable was.
I haven't measured it but looking at pictures I am sure I can build a case for the PCM and mount in under the hood in the water separator area, that is where lots of them go now anyway. There are very few connections to the PCM that don't go either to the engine or the transmission so the vast majority of that wiring will just transfer with the engine and transmission and it is all exterior to the cab.
I am quite sure there are no anti-theft or other modules that the PCM needs to communicate with so no concerns there.
As for the cluster, still thinking on that one. I would probably build a custom cluster incorporating the psom and tach from the 96 with idiot lights and LCD displays of my own design for the other indicators.
I will see about making a video of the 6.9 on cold start. Will be a few days as heading out for the weekend.
 

david85

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I thought the engine cross members were different on the diesel truck frames. Having said that, I can't see the 300-6 taking up more room than the IDI.

The E4OD is significantly longer than the C6, so the transmission cross member will either have to get moved and/or replaced (assuming the 96 is the same wheelbase). Although with your GV overdrive, I'm not sure what sort of difference you'll be facing.

This wasn't much of an issue when I converted my 86 to overdrive. I simply took the newer style cross member from the E4OD donor truck (crew cab) and drilled fresh holes in the frame to mount it wherever it "looked right". The original style C6 cross member could have been made to fit, but the E4OD cross member was a better design with fewer parts and a stiffer design. The drive shaft will also have to be shortened or replaced. If the two trucks have the same wheelbase, you should be good to go. If not, you might be able to make something work by raiding a local wrecker.

I can sympathize with getting an older diesel to run well in -30C weather. My 6.9 never saw that kind of cold under my ownership, but it does get a little cranky below freezing so I can only imagine. And when you combine winter diesel with such cold temperatures, you end up with a truck that never really gets warm and never gets good MPG in the winter. I worked in the oil patch for several years and saw the struggle to keep even late model diesels running. My Duramax service truck struggled to keep the cab warm at -20, so it was actually a step up when I was switched to what was at the time a brand new F150 (2014).

Having said all that, I still think this is more work than it's worth. The EFI six is only half the battle. Don't underestimate how temperamental an E4OD can be when the factory electronics don't all work perfect. Low miles or not, it's still a 20+ year old truck with unknown history. If rebuilding the 6.9 is a non-starter, then the cost of rebuilding the E4OD may surprise you.
 

robert alston

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howdy
i have done a 300 swap in a 1983 step side went from a non computer to a1991 computer setup
 

Eli

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I'd get the Offy intake for the 300, and either an Edelbrock carb or FiTech, and a standalone box for the E4DOA. Shouldn't be too hard.

Eli
 

catbird7

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Not real familiar with C-6 configuration however if there's a possibility of reattaching your existing and in place diesel C-6 to the 300 six banger, that would be the easiest route. Somebody here should know, "are C-6 bell housings removable"? "Is there an adapter designed to connect diesel C-6 to 300 six"? Can you or someone local fab your own adapter? Swapping just the engine would eliminate many hurdles, especially if you also converted the 300 six to a carb. I think 300 six has the same bell bolt pattern as 289 & 302. IMO, 300 six is a great truck engine, not speedy or overly powerful, but a very good robust design if longevity and low end grunt are what you're looking for. Suggest changing oil filter housing to the older style which positions it vertical. Later models with horizontal mount seem to "knock" when you first fire up.
 

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