[68RCodeConv]

I need to pull my factory C6 from my 73 vert because it is leaking. The car has a 351C-4V (stock) and 3.89 gears. The transmission has 70,000 miles on it and still shifts well. I've heard that this transmission is a real power hog and that I might be better off with a C4 or AOD. Since my motor is basically stock I'm sure the smaller transmission could take the abuse. The advantage of the AOD would be the overdrive (especially with the 3.89 gears). How complicated is this swap? What vendor did you use for the new tranny? Would I have to replace the flexplate and starter? How about the crossmember? What's involved in hooking up the shifter and kickdown?

 

[LMan]

the AOD portion of your q is a common one...Im sure a search of the archives will help you out

 

[Johnbear]

It doesn't have anything for the 351C but it says up to 500hp and I've seen adapter bellhousing http://www.transmissioncenter.net/AOD.htm

 

[Bruiser]

If you don't mind "not original", I'd go with the AOD. Very easy swap. I did it, and am using 4.11 gears. It's the only way to go with that short of a gear. I think the AOD has a final drive around .66 or .68. That makes all the difference on the highway.
I used the WinzorFox kit. Again, very easy. With the new spacer plate, the aod bolts right up. They'll send a shifter kit from Lokar so you can use your stock shifter, and you'll get a new crossmember. That bolts right in. The only thing you'll have to do is have your drive shaft shortened. I think the aod is a little longer than a c-4 or c-6. Maybe an inch or so. Maybe a good time to buy that aluminium shaft!
Good luck.

 

[johnpro]

I think the aod is a little longer than a c-4 or c-6.

Not necessarily true. I've heard that there are "long" tail shafts and "short" ones on the AOD (but haven't confirmed this). I just used my existing C4 drive shaft with no mods at all to it. I would think, if anything, he would need a LONGER drive shaft going from the big ol' C6 to an AOD.

The shifter linkage that Windsor Fox sells is their own. The TV Cable that they sell is a Lokar.

I bought all my stuff from Windsor Fox when putting the AOD behind my 289 and was extremely impressed with how it all fit.

 

[CantedValve]

351C uses a stock AOD without adapter... ask me how I know.

351C engines use small block transmissions. Thought that was common knowledge

 

[dodgestang]

My AOD was shorter than my c6.
The AOD is just as much a power hog as a c6, so if you loooking to free up HP the c4 is your choice.
There is no kickdown level, but something similar called a TV cable.
Installation is easy but will require about $300 in aftermarket parts unless you like to fab your own custom cross members, shifter linkage, reverse light and lock out wireing harness, etc.

You will also in all likely hood need a new driveshaft and an AOD yoke.

 

[GypsyR]

The C6 is the "longest" of Fords older transmissions. Also the output shaft has more splines than a C4/C5/AOD, so you'll need a new yoke at least. You may be able to keep your driveshaft and shorten it, or possibly find a used "C4" driveshaft. A new aluminum one sure would be nice.
The AOD's come in two lengths, normal for most passenger cars and 1" longer in Lincoln Town Cars and trucks. Just to confuse things, this is not an absolute rule just what is "supposed to be" in these vehicles.
It's best to buy a throttle valve cable kit from Windsor-Fox or somebody. You can rig up something, but the adjustment of the cable is critical to the operation and life of your new AOD. If it's way off, you can waste a perfectly good AOD within a couple of miles. If you choose to go AOD, best to budget for one of these kits.
You'll also need to buy, build, or modify a transmission crossmember whether you go with an AOD or a C4.

 

[sloan]

http://forums.vintage-mustang.com/forums/showflat.php?Cat=&Board=forum&Number=678953

I'm in the middle of it. I have all the parts. I'm doing some engine stuff before putting it all together.

I say AOD. You have to get some "stuff" to do it. (besides the transmission). But it would really pay off for you and your 3.89 gears.

That is.. if you drive it on the interstate any.

If its just a weekender, then c4 might be more cost effective. But I'd still do the AOD. Its "cool" and it has advantages.

..

 

[70_Cougar]

The AOD is just as much a power hog as a c6

dodgestang

Please show me where you get this information. The sole reason for this transmission was to boost fuel efficency to meet stiffer goverment regulations. John

 

[theokponycorrall]

if money is a issue go with the c-4.

 

[70_Cougar]

To say that the AOD is a "POWER HOG" is a misleading statement and sounds like sour grapes from someone who has had a "BOTCHED" experience with a AOD.

Because of the size and weight of some of the internal components of the AOD it is not the best choice for a race transmission. If you mentioned RACE in your post I must have missed it.

The AOD is a good choice for a upgrade if you desire better fuel efficiency and less wear and tear on the engine since it has the overdrive feature and cuts cruising RPM by 1/3.

There are plenty of 5.0 mustang folks that use the AOD transmission for racing however the first gear in this transmission is not as low as the other Ford autos and therefore has a handicap. A conversion does exist to install a lower first gear into an AOD. John

 

[CantedValve]

Speaking purely in HP terms, an AOD is going to consume more power to run it than a C4 will. I dont have documented evidence, but I really dont hear people going for racing applications switching to AODs in large quantities. AOD's are wonderful things. I have one. Wouldnt trade it for anything.

However, the statement "AOD's use more power in their operation. If you are looking to free up some HP, go with a C4" does not seem (even without documentation) to be inaccurate.

If this thread actually gets anymore traffic, I think you are going to find yourself in the minority.

 

[70_Cougar]

I am so pleased that you are happy with that AOD you bought from dodgestang! Any idea why he had so much trouble with it? I bet you are also glad to be done with all that carb trouble too.

I'm sure that dodgestang can round up plenty more traffic if he wants. John

 

[CantedValve]

I didnt buy dodgestang's unit. I dont know what gave you that impression. I actually went and bought an Art Carr uilt unit. Other than the specific manufacturer of the parts though, it is pretty much same as dodge's (same stall, one piece non-lock-up input shaft, etc. etc.).

Carb trouble was partly my doing. Trying to fit a carb from an old build onto this engine. The Demon I have now, while not tuned 100%, is working quite well. Thanks!