AOD is easier to install and will get the job done, 4R70W is better but not as easy to retrofit to our cars. Just my 2 pennies worth.

 

thanks, is there any specific year AOD I should be looking at? any years I should avoid?

 

I think you want a 1989 or newer AOD. That's what I have and it works well. Be prepared to change your rear end gears. I had 3.00 gears and it was too much gear. I changed to 3.55 LSD and it is a nice match. Runs at 2000 rpm doing 70 mph.

 

I’m running almost the same setup. 1967 302, AOD, 3.55 gears, and Sniper EFI. At 70 mph I’m right under 2100 rpm.

On the street it shifts through the gears pretty quick and keeps the rpms low.

 

I kind of prefer a 1984-88 truck AOD myself. They have the strongest internals. Not by much though. A "Mustang" AOD is probably the most ready to use as-is. I wouldn't turn my nose up at any 1984-93 AOD if I were going to rebuild it or have it rebuilt. The internals can be upgraded how you like.

You don't really see them around but avoid the 1983 and earlier ones. They had some issues you can kind of fix but they're just not worth fooling with if you ask me.

 

I would like to be able to have OD so he can drive comfortable at freeway speeds.

When I was a kid growing up in the sixties, the "freeway speeds" were 70-75 mph. Oddly enough, all the cars of the day (and many of those from the fifties, too) had no problem driving "comfortably" at those speeds.

Do you want to know the reason why we have overdrive transmissions? It's called the U.S. Government telling the automakers "you have to produce a fleet with a 'corporate' fuel economy average of xxx". Same reason we have low-tension piston rings, 0W engine oils, etc.

If the concern is fuel mileage then maybe an OD transmission makes sense. From my own perspective, I (and my car) are more comfortable at 3,000 rpm at 70 mph than 1,800 rpm...

 

" I had 3.00 gears and it was too much gear. I changed to 3.55 "

I had to do this too after the AOD addition. If you leave it 3.00, it will lug like crazy and get poor mpg's

Of course you could just leave it in second (still goes to third) and drive around without the O.D., unless you are going to be going 70 + on the freeway.

 

I just love that purr when the engine settles down into OD at about 50 mph. Others love that 3000 RPM howling cruise. Neither is wrong. OD does help a lot with mileage if the car is going to be used for other than quick trips just for fun.

 

I'm contemplating installing an automatic overdrive in a 65 Convertible and am learning. Since you will be going to EFI, is there any benefit going to an electronically controlled AOD transmission?

 

If you're referring to the 4r70w, then yes. With the 4r70w you have the benefit of better gearing, stronger, more reliable internals capable of handling more torque, no TV cable which if misadjusted can quickly toast an aod, no aod shuffle, the ability to shut off o/d with the push of a button, and with a good controller the ability to adjust shift points.

On the down side, the controllers are a bit expensive and require a bit of wiring knowledge. Also, I believe '04 and later transmissions don't have gears on the output shaft for using an old style speedometer cable and gear but there are adapters available to use a speedometer cable with the vss unit.

 

I took my 68 289/C4 on a 500 mile trip to the NPD car show and back last Jan. It was very comfortable on the Highway at 70 mph and even an occasional sprint higher. Unless you plan a lot of highway miles, need the better fuel mileage, or you C4 is shot, I'm not sure the cost is worth it. I your C4 is good I would consider driving it as is until the C4 needs replacing/rebuilding

 

Highway cruising in a stock mustang is not that bad, the RPMs are reasonable. Remember the speed limit back then was 70, so they came with really short gears like 2.80 to 3.20 which kinda suck for stoplights and quarter miles.

Iput a 92 AOD from a mustang in my 67. Noway near as easy as dropping in another C4, but once complete it is a better drive. I went with 3.89 gears in a nine.

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I am rebuilding my Son's 1968. I just pulled the engine and transmission. I would like to be able to have OD so he can drive comfortable at freeway speeds. AOD transmission the answer? The engine will have some modification but I need it to be a reliable daily driver. We will be adding EFI either Holly or FiTech not sure what one yet.

Thanks

Not what you are asking for really but I will give you my take on this. Our '68 came with an AOD already installed by the P.O. It felt sluggish and shifted way too soon. We installed a 3.80 gear set and it helped. I had a custom converter built for it and it was better. I then had Lentech build us a valve body. After all those mods it was just "O.K." Under light power it would shift into second before you were through the intersection. WOT was good as it would stay in first longer and hit second fairly hard. Overall I did not like the AOD. Yes, highway rpm's were nice and low but most of our driving was in town.

Ultimately I took out the AOD and sold it all off to finance a T5Z swap. Much happier with it now and a LOT more fun to drive. I know there are a lot of guys out there that love the AOD but my advice would be if you are thinking about swapping trans. then really look at a 5 spd. conversion.

 

Thanks for all the feedback. the car is for my son, he is at Westpoint and he can't have a car for another 2 years, but I want to get it working for him when he comes home for the holidays. I expect he will be doing a lot of freeway driving on the east coast. We are on the west coast so my expectations of driving conditions may be wrong. I am more of an off the line power guy than top end, so I need to keep my ideas of what I would like in check. I guess I am looking for a solution that will give me good (better than stock) off the line performance with a decent top end.

Thanks again.

 

T5Z with a 3.80 rear gear...........fantastic first and second gear acceloration and a 5th OD gear. Cruise at 70 in fifth around 200-2100 rpm. I'm biased though.

 

I've had both the C4 and AOD (from a 92 Mustang GT) in my 68 289 car. I swapped to AOD because of the praises sung here over the years and the high revs I was getting from the C4 on the freeway (70-75 MPH). My car currently has the stock open 2:79 rear 8" rear so I am currently experiencing exactly was Rebel Racing described. Shifting way too soon, sluggish down-shifts. Don't tell me about adjusting the TV. I've adjusted it every which way and it doesn't improve the shift point noticeably much at all despite what people will tell you.

My next plan was to change rear gears to a factory 68 Mustang 3:25 posi carrier that I have in my shed but am now bummed to hear that it might not help much (even if I change to 3:50-ish??). This kind of confused me since I thought that the 92 GT I took the AOD from had a 3:25 posi so why did that car work with the AOD better (I presume)? I rebuilt the AOD via the Bad Shoe videos so I guess it's conceivable that I got something wrong but it otherwise works fine. Just early shifts and sluggish response.

Aaaanyway, I just use my car for cruising so it's not a huge deal. I must admit that I like the improved fuel economy but I'm not the most economical driver so I really have to be responsible to get mileage better than about 18 with the AOD. I was getting around 12 with my C4 so it's an improvement I guess.

 

Is the trans original to the car? If so I would leave the trans in the car. I remember cruising the highways at 75 with a 3 speed auto with no problems. At one time my folks owned a 68 Camaro with a Power Glide (2 speed auto for those who don't speak GM trans) and we went on trips from Chicago to Yellowstone Park and other far off places with that car without issues.



It's bad enough you have fallen victim to the school of thought that you need EFI for the car to be a reliable driver, don't fall victim to the it's got to have AOD to be drive able on the highway.

 

It's bad enough you have fallen victim to the school of thought that you need EFI for the car to be a reliable driver, don't fall victim to the it's got to have AOD to be drive able on the highway.

Agreed.....when we first bought the '68 I was all hot to ditch the carb and go EFI. Never did that swap and am glad I learned a bit about carbs. To me it just looks cool to still see a carb on these classics. Not saying I will not go EFI eventually but just don't see a great need for the swap right now.

 

I agree that the only reason to swap a different trans is to go to a manual. That is what I intend to do at some point. I will wait for that to change my gearing as well.

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I agree that the only reason to swap a different trans is to go to a manual. That is what I intend to do at some point. I will wait for that to change my gearing as well.

Not the ONLY reason, another valid reason for the swap is if you want taller rear end like 3.7 or higher. I compromised from a 4.11 or 4.30 to install a 3.89, but even a 3.89 would make a lot of RPM for a highway cruise at 75mph. There's a highway 2.5 miles from my house that has an 85MPH posted speed limit, that would be unbearable with a big gear without overdrive.

 

A lot of people have issues with AOD shift points. I used to advise people to buy a (cheap!) geometry corrector bracket for their Holley or Edelbrock carb and THEN adjust the TV. Also a higher than stock boost valve from Sonnax in the valve body I've found to be a great help. But I'm ignored apparently. People keep complaining but not one has actually tried what I said and reported back either way so this is probably the last time I care to mention it.

 

AOD performance will differ depending on what vehicle it came from.

AOD shift points are controlled by a little valve called a governor. It is bolted onto the tailshaft, inside a little separate housing that comes off. It operates based on hydraulic pressure and RPM. There are three versions of the governor:

Low speed (WOT shift at 4200 RPM). E8AZ-7C063-A. These came in "low po" 302-powered cars like the Crown Vic, Grand Marquis, and Lincoln Town car. An AOD with this governor will shift before you can blink and drive you nuts. I bet anything that AOD in Rebel Racing's car was this version.

Medium speed (WOT shift at 4500 RPM). E2AZ-7C063-B. These came in trucks.

High speed (WOT shift at 4900 RPM). E8ZZ-7C063-A. These came with HO 302 cars - Mustangs and Lincoln Mark 7. This is the one you want. Unfortunately it is completely obsolete from Ford. I tried hard to get one and it was unobtainable. Finally found one on EBAY.

So you can make sure that your AOD comes from an HO car, or you can get a good AOD from whatever car and swap in the HO governor. The good news is, it's a really easy swap.

This thread has info on the swap, specific to Crown Vic/Grand Marquis. It can be done with the trans in the car. I did it on my 89 Grand Marquis, which I converted to HO specs.

{transmission} AOD Governor swap.

Another option is the Transgo shift improver kit, available from Summit. This will bump your WOT shift up to about 5500. In addition to the governor mod, it includes a valve body mod. I have not done this but I hear good things about it. And it's only about $50.


All that said..... Automatics suck! Put a T-5 in it.

 

I think you mean TransGo's "AOD HiRev" governor kit. A valve and a couple of springs. It runs about $40 and does basically what it says. The one car I currently have an AOD in just about redlines at 5500 and we don't drive it that way anyway so personally I have no use for that kit. People with higher revving engines that drag race more than a little like it though. Not a whole buch of people drag racing AOD's these days though.

TransGo also makes a "Shift kit" which is more like what we think of that tweaks the way the transmission works with an ey towards performance. It also runs about $40 and DOES NOT include the HiRev governor parts.

Lastly, TransGo also makes a "Shift Corrector Kit". (My favorite). It basically corrects some factory stuff that should have been done better to start with and has rather small effect on how the average driver perceives the transmission to be working. About $61.

Main point is that if you decide you want a TransGo "shift kit" you want to be able to specify which one as they sell these three different boxes that fall under that label.