I am looking to buy a 86 F350 4x4 crew cab in great shape, but the motor is shot and half taken apart and scattered. The same guy has a 92 f450 with a nearly new 7.3 crate motor in it. Said I can have the pair for 2 grand. Will the 7.3 just un bolt and drop right in the early truck? Or is there weird wiring and such that needs to be done? Also will the 6.9 automatic flywheel fit the 7.3? Please advise I gotta make this happen as quick as possible.

 

The 7.3 will bolt right in the 86, but the wiring harness is different. I'm not sure how much different, but I recall Dave S. saying he had toclip the plug ends and slilcing the two together. I'm not an auto guy, but I'm running a SMF conversion for a 7.3 on my 6.9. I would think the 6.9 flex plate would work on the 7.3.

 

I did the swap from 7.3 to 6.9. Your glow plug sustem will be different, but compatible. Spades lugs on the 6.9 bullet on the 7.3. Glow plugs will swap from engine to engine, best bet take whole glow plug wiring, relay and all from F450, better system, but you can just put your plugs in 7.3. Supposedly the balancer and flywheel balance different. Just make sure you use what came with engine (I have read that swapping both works also). If they are automatics the 92 probably had an E4OD. Different flex plate but flywheel should be samebolt pattern (yes auto uses flywheel). Use flex plate from original.

 

The 6.9 uses a flywheel flexplate combo. The balancers and flywheels do not interchange between the 6.9/7.3 they will fit but make no mistake they won't work. The 7.3 has a heavier rotating assembly due to the larger bore.

 

My 7.3 an 6.9 both had flex plate flywheel combos. 7.3 from 89 f250 had a C6. Don't know if E4OD used same set up for sure. If not I think I still have 7.3 C6 flywheel laying around, If you need it let me know and I will see if I can find it.

 

ok so it will need a 7.3 (auto) flex plate as its currently a 5 speed. So there really is nothing major as far as wiring etc. I have plans of just trying to adapt the whole setup over if its not to much work, along with adding the hydra boost brakes. I might as well rob whatever I can from the F450. So the injector pump wires and everything else should just cross over? Also the 6.9 has a ATS turbo setup, I asume the exhaust manifolds will work on 7.3? Sorry I am cramming all the questions in, but only have a few hours to make decision before the other guy gets it. I know the current owner so the deal is legit, I just dont want a nightmare project. But a motor R&R I can live with.

 

I think you're right, but in later years (E4OD) had a one piece jobby IIRC

 

Well just traded my Bronco and 500 for it. Here I go again. Looks like I will be back in the idi maddness.

 

Wow 2 grand for two trucks sounds like a prety good deal! You might want the aux springs off of rear axle of the 450 too. If not i might be interested in them for the right price.

 

And I'm sure ALOT of guys here would like to know where you are going with that ZF-5. . . . . . .

 

Im not sure what I will do with the 450. Its in good shape but only 2 wheel drive. If it was 4x4 I know exactly where the zf would be going.
In the meanwhile I still have to locate a c6 flex plate for a 7.3. Maybe I can trade a the flywheel and clutch for it or something. The 7.3 only has 6000 original miles as it was a crate engine just last year. So everything on it is new down to the belts. Kinda cool! I am excited to get it in there, but starting to stress on where I will find parts

 

The ZF-5 in that 450 is the 4x4 version of the ZF-5....throw a transfer case on it and go for it....and if you need parts...i got parts out the wazoo....

 

Its the 4x4 version? would my automatics transfer case bolt up to it? What about drive lines? I am kinda on a budget so I am trying to use as much of what I already have. but having a 5 speed would be nice. I have the whole truck so pedals and such are there.

 

All F450 are 4x4 trannies, but instead of a transfercase mounted, they have the parking brake mounted on it.


You can simply unbolt the park brake drum, and bolt on a transfer case, and bam, you got a 4x4 tranny




And you can't use the 92 pedals in the 86.


80-86 is one set of pedals, 87-91 is another, and 92-97 is another. Non will interchange.


You'll need a 82-86 pedals, (80-82 was a mechanical clutch) and will not work with hydraulic setup.

 

Ok, good info there thanks! It seems the 450 trans has a issue anyways with getting stuck in 3rd. Thats why it was parked. So with that and pedal issues and such I will most likely stay with the auto box. Its fresh anyways.