I currently am concidering a 7.3 idi to transplant into my 79 Econline short box. Curious as to if this motor is the same blot pattern as the gas big block Fords? Does anyone know if the 7.3 idi or Powerstroke version ever come with a 4 speed auto be it either AOD or EAOD?

 

The IDI bell housing pattern is not the same as the BBF or SBF, It is unique to the Diesel.

The IDI came with the Computer Controlled E4OD Automatic with Overdrive.

-Enjoy
fh : )_~

 

So with a transplant like that I would have to custom wire the computer for the EAOD at least? My understanding is that the idi fuel system is mechanically controlled making that motor better for what I am trying to do. The least amount of rewiring the better.

 

If custom wiring is needed for the trans anyway would I be better off to work with a Powerstroke over the IDI?

 

The Powerstroke is going to require you to use the entire engine and dash wiring from a donor vehicle. The IDI is simple to wire and there are a couple of aftermarket trans controls (I'm using the Baumann) that will be much better than the stock unit.

 

If you're pulling a 7.3L and E4OD together, you could grab the trans harness and controller with it.

I think that's all you need.

 

Just to be clear, there is no such EAOD transmission.

There is the AOD, which is an all mechanical controlled 4 speed overdrive with 3rd and 4th always locked (1980-1993)

Then there is the AODE which is based on the AOD only computer shifted with part time lockup for 3rd and 4th and lower overdrive ratio (1993 and up)

Both versions of AOD are only available behind the ford windsor series small block engines or the 4.9L six which shares the same bolt pattern. The term EAOD might cause confusion and some one on the other end may assume you are talking about the AODE.

The E4OD is available in small block, big block and diesel bell housings. Never offered in a mechanical version. (E4OD = Electronic 4 speed OverDrive, AOD = Automatic OverDrive, AODE = Automatic Overdrive Electronic)

I'm also running a Baumann control system and it rocks but its also pricy. If you try to retrofit the newer OEM computer and harness, you need to install everything, and I do mean everything that is required for the computer to be happy. Donor years are 1989-1991, do not go any newer then that because that would require a rear end swap for the vehicle speed sensor on the differential. Older ones have the VSS at the tranny end of the speedo cable. My 1986 F250 had it ready installed for signal to the automatic speed control, but I don't know of 1979 will have this. Although even the baumann setup would require a VSS (either version will work).

 

Another option would be to go with a C6, no wiring really needed (backup lights etc of course) and can likely be mated with the speedo cable as well if you have your original dash. Of course you lose OD, but if you're not looking at high mileages, maybe that's not a concern for simplicity.

 

Now that is some good info thanks every one. Here is the odd thing. The truck is a Feb 89 F250 7.3 4x4 with a manual 5 speed. Now even though it is stated eariler that the post 91s used a speed sensor off the rear axle, this truck does have a strange electrical conection going to the differential. Could this be the speed sensor?

 

Thats for the ABS on the rear axle and yes it is basically a VSS device. After 1992, ford eliminated the speedometer cable and cable mounted VSS resulting in the RABS sensor also feeding signals for the speedometer, automatic speed control and computer shifted automatic transmission signal (if equipped) as well as the ABS, thus simplifying things and reducing production costs.

Before the ABS on the rear end, trucks had a load sensor that send a mechanical signal to the brake line pressure so the more the truck was squatting down, the higher the brake line pressure on the rear end would be. I think 1987 was the first year RABS was introduced to coincide with the new body style (I suspect the E4OD was also planned for the same year but it wasn't ready so 1989 was the first model year that officially had it). That would mean that trucks build during 1987-1992 would have 2 vehicle speed sensors operating in parallel.

We have heard from one source here that swapped rear ends across the 1992 transition year and had no issues running the E4OD. I think in that case it was a truck newer than 1992 running a rear end and ABS/VSS sensor from one that was older than 1992. Based on that, the VSS really didn't change after 1992, but the computer and related wiring likely did.