7.3L IDI E4OD to 300 I6 NP435 trans swap?

direwulf23

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Okay, I just joined last not and I realize I'm already blowing up the forums. I did truly search for applicable info in the forums but did not find anything close enough (4 hours of searching/ reading).
I'm looking at a 1994 F250 with a 7.3L/ E4OD. Everything is fine right now but I know very well the reputation of the E4OD behind a diesel. I couldn't really afford to rebuild the tranny or purchase a used/rebuilt. I do, however, have ample access to a full truck with the NP435 but it behind a 300 I6. They are both 2WD.
I have seen people talking about the NP435 behind the 6.9L, but not the 7.3L. I wonder about the swapping of gasser tranny to diesel and the engine being a 300 I6. I expect quite a bit is involved but is it doable? How much swaps over/doesn't? Is the past needed going to make it completely non viable?
Sorry for blowing up the forums and thank you to anyone who can add in.

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ToughOldFord

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6.9 and 7.3 are the same engines, they just bored out the 6.9 and made a few miner upgrades and the 7.3 was born, so if it can be done to the 6.9 it could be done to the 7.3.

I don't see that what you want to accomplish would be all that hard, you would need a bell housing of a diesel with the T19, the 300 bell has no prayer of working, and then figure out what clutch/flywheel you'll need for the combo you want.

But if you have the option, looking for a ZF5 really is the best way to go, you'll get the dependability of the manual with the benefits of overdrive.

Or if you're looking for a quick and cheap swap just get a diesel T19 when you get the bell, then it'll all go together easily and won't cost much, there's almost no demand for the T19 (no overdrive) so they go pretty cheaply.
 

opusd2

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With the right gear ratio and tire size the 4 speed should be ok, but an OD is a nice thing to have. I've never owned a ZF5 but have several 4 speeds in my Fords and one behind a 360 FE that I used to pull EXTREMELY heavy loads on the farm with, and never any issues with the tranny. They are tough. Though right now I have a C6, 4.10s, and 305-75-16s on the truck and even though the speedo is correct and the truck pulls like the dickens, an OD would be nice for the longer runs on the super slab
 

direwulf23

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Definitely would prefer an OD of course, but I have a full truck with the np435 that is not being used otherwise

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freebird01

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the ratios are off in an NP435 for a diesel. can you make it work? sure.... couple people have done it... Dieselcrawler has one in his crawler....I know another guy that swapped a C6 for an Np435 in a truck i sold him....

you be better off finding a T19 or a ZF5 and leaving the F150 alone... i got a 2wd ZF5 ill sell you if your anywhere closer to Indiana

you would also need to find a diesel bell housing....which is completely different from a small block bell. the diesel bell housings can be difficult to come by for the 4speeds.
 

riotwarrior

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Welcome to the forum.

Basically you will need a T19 bell housing, and flywheel, crossmember and clutch setup to use the NP435 and new drive shaft/s. not sure if you have a one or two piece shaft. You will also need a pedal assembly from a standard truck of your diesels vintage and the hydraulic clutch setup.

There is a whole bunch of electrical crap to deal with too, for the tach to work and such something about jumping wires and such. Also you will need to locate the reverse lights to setup to function correctly.

Being that it's an E4OD it's likely 4:10 gearing which means with the NP435, the gear spread will suck for a diesel as it' a wide ratio transmission compared to the T19 close ratio diesel. It will work, just not ideal.

It would be advantageous to find a ZF to retain OD and decent mileage and lower your revs on hiway!

In answer to what swaps over..

The NP 435 and the shifter...that's all you can really use based on the info you provided, we don't know the year of the donor truck with the six cylinder, and that would be helpful!

Hope this helps...

..and a T19 swap...is essentially the same swap as a NP435 so search that out too!

Again welcome to the forum.

Al
 

direwulf23

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I definitely get all of that. My research into using the np435 is that I have it and I want an immediate backup plan for the E4OD should it fail. I will certainly be on the look out for a better fit. Unfortunately, I'm in Arkansas

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direwulf23

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I really appreciate your responses! Of the forums I've read this is the one I've enjoyed the most. I realize there's a lot of info that is unknown and very important.
The diesel is a 1994. The donor is a 1987 F150 with a 300 I6 and 4 spd with granny. Honestly, I don't specifically know it's an np435 but I am pretty certain.
I definitely want to move to a manual as I want/need the truck to be as bullet proof as possible, and I just prefer manuals. Also, I drive diesels, heavy duty straight trucks, for a living. I know diving a diesel but I don't know owning a diesel

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Coyote_Red

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You can have a 460 bell housing modified to fit behind a diesel. Search out the typ4 mod. it involves reaming a few holes, moving a dowel pin or two, and drilling some new holes off center from the old ones. Is the first gear synchronized in the four speed? If so it is a T-19, if not you have a T-18 or NP435. If the top cover (where the shift stick goes in) is aluminum it is a NP435, if it is not you have a T-18.
 

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