Mercury Cougar Owners banner

1 - 5 of 5 Posts

·
Registered
Joined
·
406 Posts
Discussion Starter #1
I'm looking to totally boost up my power in my 68 cougar XR7 as most of you know. I've asked about what engine I should put in and I think I'm pretty set on a 351W stroked to a 396. So now I'm looking at transmissions. Right now the car has a c4 automatic. I'm thinking with over 400 hp, I'm going to need to beef up that transmission. Really, I'd like to put in a manual transmission, a nice 5 speed would be great, but I don't know how hard and costly it's going to be to drop in a manual transmission. Has anyone ever done it? Also I'm looking to have the ability to still be able to fully restore the car when I'm done being a kid, so I'm keeping that in mind to. So I'm looking through transmissions and I see this transmission that has a manual/automatic valve body. When it's in drive it's an automatic, but when you shift into a low gear it becomes manual and you need to shift after that. Does anyone know how these things work? Should I just convert to a manual transmission? Or can I just get away with a shift kit? and that's another thing I don't really understand, is how a shift kit works and what are their advantages? Thanks for your help, because I sure need it!
 

·
Registered
Joined
·
1,832 Posts
Chad, since you car is already an auto, a muanual switchover requires alot of changes. The best way is to have a complete doaner car there so you have all the pieces you need. Besides the clutch linkage itself it apears to be quite invloved to switch to the t-5 5 speed. Call National Parts Depot, there California toll free number is 800-235-3445 and get there catalouge. They have all the pieces listed for the change over to a t-5 as well as a aod automatic switchover witch sounds like a maybe better idea.Remember they list Mustang parts only but these driveline parts are the same as your Cougar. There are alot of people who swear that a rebuild and some good parts in your c-4 is they way to go, and they maybe right. It all boils down to how much you want to spend (like always). The aod switch dose make some sense to me if you plan to drive the car alot as the overdrive will help the over 400hp monster get some decent gas mileage with out hurting low end performance. I'm sure there will be a couple fellows reply that have done the switch and can help you out with advice there. Cougar AOD is one and he likes the Aod trans. Personaly if it were me and I wasnt going to use the car as my daily driver, I would probably try to find a c-6 and swap it in place of the c-4 and when your done playing kid it will be an easy swap back to stock. I will leave some one else to expalin the shift kits to you as I understand them myself, but someone else can probably explain it to you better than I can. mm
 

·
Contributing Sr Motorhead
Joined
·
5,470 Posts
Automatic trannies

Chad,

First of all, horsepower is not a determining factor for power handling limitations, torque is. Stroking a 351 to a 396 will create a torque monster. You're gonna have the torque of a big block.

There are some racers out there who swear by a C-4 that are running in the 10s and quicker, however, they really don't care about longevity. A C-4 has a lot less rotating weight than a FMX or C-6, that generally makes a C-4 car quicker. A FMX or C-6 have the built-in torque handling capacity of a built engine and will last longer. What trade-offs are you willing to make? Let's put it this way... Ford never put C-4s behind big blocks. That should tell you something! The lightest-duty tranny they put behind a 390 was a FMX. Heck, even 351-4V cars had FMXs. So do many 302 cars! Even my 66 Comet with its 289-2V has a cast iron Cruise-o-Matic (aka FMX).

A car driven on the street will be shifting a heck of a lot more often than a race car. You have to take that in mind. Also, there are many tricks that can be made to the internals to take the slop out of the system. Then there are ways to make the clutches react faster, harder, etc. If you have never built up a transmission for all-out race duty, I would strongly suggest leaving that to the professionals.

What I would recommend to the novice is the installation of a shift kit. Don't get the cheapest kit. I believe B&M has both a Shift Improver Kit and a Trans-Pak. The Trans-Pak gives you many more options, mild to wild. I believe you can even make your existing valve body into manual-only if you so desire. I chose the middle option for my C-6s. That allows automatic functioning in Drive, but full downshift capability at any speed if selected manually. I found that out the hard way...

Before the installation of the transpak, if I were to manually select L while travelling down the freeway, the transmission governor would only let it go down to Second. Afterwards? Well, one day, when coming back from the track, I was messing around with one of my buddies on the freeway. He came charging up next to me so I crammed the shifter down to L like I always had to downshift (my carb did not have a downshift linkage). The transmission obeyed by going right into L -- at 60mph! :eek: Man, I thought I was gonna blow the engine! After the smoke cleared, and the car stopped bunny-hopping, I realized what had happened. The tranny went into L and the rear tires obeyed the engine rpm, so the rear end was sliding and hopping all over the place trying to get traction again until the engine speed caught up with the tire speed. I'll never make that mistake again!

OK, Like MM, I would advise against putting in a manual transmission. Too much is involved to do the swap. You'll be much better served with a stout automatic. Use either a FMX or C-6. They won't be all that hard to find. Almost all older pickups and vans with small blocks will have one or the other. Time for a little junkyard scrounging! Then again, if you want any sort of gas mileage out of your car, you might consider the AOD. Be careful though, you don't want an electronically controlled AOD! You can use up to and including a '89, I believe.

Good luck!
 

·
Registered
Joined
·
1 Posts
manual/auto valve bodies

Chadinman:
I have a '69 Cougar with a 392 stroker from Ford Power Parts. I originally thought of going to a Tremec to have an overdrive that would hold together but finally settled on an AOD built by Mark - CougarAOD. He put in all the good parts and set up the valve body to shift like a trans is supposed to. I love the way the AOD shifts behind my 392 and would recommend it to anyone especially if Mark puts it together. My only problem has been clearance around the Hooker headers that other members have also had a problem with. I have no regrets about the AOD and really recommend Mark as a trans builder and source of information.
 
1 - 5 of 5 Posts
Top