66 c4 to aod

jb1dsl

Member
May 24, 2004
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Marianna, Fl.
What all do you have to change to put a aod in my 66 fastback that has a c4. I have to pull the tranny and was wondering should i rework it while it is out or put an aod in for the overdrive. I have to replace the shifter fork in the c4 because right now it will not go in to park. The transmission needs to be gone through so i have to make a decision. Original c4 or modern aod???!!!
 
I have planned from the very beginning to replace the C4 in my 66 with an AOD. The first three gears in the AOD are almost exactly the same ratio as those in the C4, yet you add the OD gear. You can now replace that low ratio rear axle ratio for something far more desirable from a performance standpoint, without having to worry about high speed cruising. You can run a 3.55 or even higher rear and have your engine running at 3500 rpms at sixty mph.

Here are two links to information I have collected. This is a no brainer :shrug:

http://www.baumannengineering.com/aodefund.htm

http://www.themustangshop.com/c4toaod.cfm
 
To replace your C4 with an AOD, i know you need a different transmission crossmember. The C4 flexplate will not fit unless it is a 164 tooth one. If you had your engine built and it was balanced to your flexplate/flywheel...I wonder if changing it out when swapping a trans is a good idea. Definetly a consideration if you have had this done.

My question to some of the people that posted before me is....why dont you see more AODs in drag racing if it is superior to the C4? Or is it superior for daily driving rather than performance and drag racing? I know it weighs a lot more too. I know a lot of guys in NMRA and that run FFW run a beefy C4 rather than an AOD. I had a Lentech AOD in my 90 Twin Turbo car and loved it. Just a lot of dough to shell out for one.
 
You don't see AODs in drag racing because you don't need overdrive on the track and most of the cars don't see much road time if any at all. You can build an AOD to take a decent amount of HP but the C-4 is stronger and weighs less. The AOD is what you want for a street car to take advantage of the overdrive but building one to take large HP is going to be pretty expensive.
 
Ronstang said:
You don't see AODs in drag racing because you don't need overdrive on the track and most of the cars don't see much road time if any at all. You can build an AOD to take a decent amount of HP but the C-4 is stronger and weighs less. The AOD is what you want for a street car to take advantage of the overdrive but building one to take large HP is going to be pretty expensive.


the aod can be built to handle even more power than a c-4 could ever think about but yes it is damn expensive. lentech sells and aod that will handle like 1400 hp, but it runs about 5g's