FMX swop to AOD

Hey guys
I have been researching about doing a 72 FMX swop to a AOD.
I have a 351c in my 72 cougar convertible. I have rebuilt the motor. Now a V4 with long header. I have 2:75 gears but plan to change to at least 3:30 and or up but no to crazy. She a cruiser not a racer. But I’d like to have a little more jam on take off. You know once in awhile. I’ll get rear end gear once I have the transmission in house.
Reading all those post on overdrive has me pea brain spinning! Back and forth, back and forth! What I do know is I don’t want a add on computer! Like I said it’s not a racer so I don’t need to upgrade the internals.
What I think I would be looking for is a transmission out of a 86-93. It takes a tv cable. But one of the things I don’t know is from what cars ( that will bolt up to my Cleveland) which cars are better the the other ( for internal gearing, out put shaft length).
Can I use my own flex plate and yoke?
What I’ll need for my floor shifter to hookup to the new transmission and how do I get the reverse and neutral switch to work as it should. And if there’s anything I’m forgetting let me know. Thanks

Overdrive gears are fantastic. So do your due diligence and keep the faith. I’d budget for having any AOD that you find rebuilt. Hence you can decide if A different 1st gear ratio is needed. A couple decades in the field aren’t kind to the AOD or electronic AOD. Not sure about torque converter. If you have a car friend that is comfortable wiring up relays and fuses they should be able to get your reverse lights and neutral lock out working like factory.

Good luck!

Thanks for the advice. YouTube is good for some of this but not all is there so it’s all about the research.

I think just about any AOD that you find will fit. They came behind th 300 6 cylinder, the 302, and the 351W. All of those have the same bellhousing bolt pattern as your 351C.

If you don some searching on this forum, you will find a lot of info for AOD swaps.

5.0 Mustang is a good candidate for AOD. Has short tail and decent internals.
Lever on side of trans will need to be changed to match the throw of your stock shifter.
If you get a short AOD, driveshaft length is good. Slip yoke need to be changed to smaller 28 spline. FMX and C-6 are 31.
FMX flexplate is same as AOD----leave well enough alone.
Not sure on 71-73 for crossmember. 67-70 require modifications.
One cooler line needs to be revised.
With FMX, your neutral safety switch should be in the shifter in the car. C-6 has n/s witch on trans. If your n/s switch is in the shifter, than there isn’t anything extra needing to be done.
When you get an AOD. Get the dipstick and tube as well.
You’ll need a Lokar KD2AODHT cable. Also, remove the pre-load spring in the AOD for proper Lokar cable function.

Trying to make this quick, there are probably a few things I am forgetting.

Just to make sure we r on the same page.
86-93 mustang would be the transmission is should be looking for!
As I’m sure a read in a thousand post all over that the mustang has better shifts between gears and the over all tail length and the torque inverted. The yoke spline 31-28. How do you change that? Use the yoke fro the mustang transmission?Correct me if I’m wrong!
And a Ford 9” rear end up grade gears recommendation would help me out. Mine r 2:75 and would like to change to 3:30 up to 3:70. If there is such an animal. Any thoughts on a nice gear size to give her a nice kick in the pants on take off but not a street racer if you know what I mean:)
If there is anyone that has the transmission and 9” I’m looking for a willing to sell. Let me know. I’m on a limited budget. Wish I wasn’t but with time the way they r things are tougher
Thanks for your inputs

You can use any AOD, but alterations to the trans will need to be made to best suit you Cougar. The Mustang 5.0 AOD from 86-92 has about everything you need.
FMX and AOD yokes are different. The FMX is 31 spline. The AOD is 28 spline. If you are pulling an AOD from a junk yard, get the slip yoke as well as dipstick and tube.
Your FMX and the short AOD are both 30 1/8" overall.

The most popular gear swap for use with the AOD is a 3.50. A bit of performance and still great on the highway. Here is a calculation for you. Due to the .67:1 overdrive ratio in the AOD, if you were to install a 4.11 rear gear, the car would cruise as if you had a 2.75 gear in the rear with a 3 speed trans.

And the 86-92 mustang transmission has a tv cable? Will it hookup to a carburetor? I’m sorry for asking so many questions to you and everyone else. I just want to do it right the first time. I have a lead on a 86 mustang V6 3.8 aod. This is where I’m hearing “you’ll need a computer to run it. I won’t hookup to a carburetor.”

If this is a good compatible aod that the bell housing will match up to my Cleveland and perfect replacement of my FMX transmission and flex plate it the same. Just need a tv cable and the yoke. I’ll purchase this transmission. I guess what I’m saying is for you guys to say “ that is the transmission you need and it will hookup to your Cleveland!” If this is the case. I will buy it. It does have 144,000 kms /89,500 miles

AOD is not electronic…ever. It requires a Throttle Valve cable or rod to operate. --------The AOD’s successor called AODE was introduced around '92 in Lincolns (93 in Mustangs) and is computer controlled. AODE was later renamed 4R70w.
While the 3.8L Mustang AOD will bolt in, it has one less clutch per pack than a 5.0 AOD. It will also have a “C” sized OD servo that is the smallest and weakest OD servo. It will work, but not have the holding capacity that the v-8 version has.
86 is the first year with a decent valve body, but it is lacking in some other areas. The later the better on the trans due to other enhancements. You should target an 89-92 AOD from behind a V-8.

If the trans is being pulled from a complete car, also get the block to trans spacer plate and inspection plate.

Where are you located?

89-92 AOD got it! Out of a V8. got it! And Im taken it that Ill need the Flex plate, plate between the motor and transmission, TV cable and yoke.
I’m I missing anything?


Do NOT take the 5.0 flex plate. It is a different balance than your 351c engine requires.

----Spacer plate with inspection cover.
----Slip yoke
----Dipstick and tube
----TV cable

Got it! Just use my original flex plate

I don’t think you can use your flex plate (flywheel) because it is too small, you will need one from a late model 351 engine that is a 28 oz balance.
Count the teeth on your flywheel, you might have the right one, the flywheel must fit the block plate for the starter to line up with it.

They are both 164 teeth.
Back in the day, I bought the AOD E0AZ- flexplate that everyone said was needed for the swap. Comparing it to the FMX flex plate, it was exactly the same. No reason to change.
However, for people that are swapping out a C-4 with a 157 tooth flexplate, they will need to find a 164. Or when swapping out a C-6 flexplate. The C-6 flexplate is 164 teeth, but it is the wrong offset.

That’s good to know!

Any engine balancer worth anything can balance the new flexplate to the old ones specs.

That is true. Luckily, he can continue to use his original as it would be a waste of time and money to buy the wrong one then have it altered to fit his engine.

I get the flex plate part but what is the difference in the plate between the transmission and the block from the old transmission to the new? If the Transmission bell housing bolts up then why would the plates be different?

I have read that AOD’s for carbureted should be per 86. Is that so you don’t need an added lever on the carb or is there another reason?

I have a chance to buy a Transmission out of a 92 Crown Vic police exceptor.

Is this a good AOD for my 72 351c FMX swop?Sorry for all the question! just want the right transmission