That's another one of those questions where the answer is, it depends. It's just one more part of the puzzle with pieces like tire size, speed desired, rpm range the engine is designed to work in, what the vehicle in question is intended to do, etc. The factories have been using od trannies for decades with final drive ratios at 1 to 1 anywhere from 2.80 to 4.56+. It's more important to have your regular gearing work properly when the vehicle is at work, and use the overdrive gear simply to lower the rpm's at high speed for economy purposes. A typical o/d is going to reduce rpm's by about 30%.

 

theres a few out my way on the west coast

Ford C-4 transmission
or
c-4 transmission


Drive out here, cruise the pacific coast highway, drive home with a tranny.


Good luck.

 

A 3:70 would be ideal but even something in the low 4s would not be bad. I wouldn't want anything less than 3:50 minimum with an AOD. I ran a 3:00 gear with a 700-R4 some years ago and the OD didn't kick in until 55 MPH.

 

Those are the kind of deals I'm looking for but on the right coast...

 

C4 introduced in 1964. Used in, for V8 examples: 260/289/302/351C/351W passenger cars thru the early 1980's (except 1964 Falcon 260's which used the anemic F-O-M 2 speed).

1969/79 F100 302 & 1975/79 F150 302 / 1980/83 F100 (only) 302 / 1969/74 Econoline 302 / 1966/68 Bronco 289 / 1969/77 Bronco 302.

The length of the output shafts and extension housings used with all A/T's vary by specific applications.

The C4 has 11 trans pan bolt holes, the FMX has 14, the C6 has 17.

In 1978/79, Ford offered the C6 with the 302 as an option in F100/350's. It was standard equipment in 1980/81 F150 302's. AOD introduced in 1982.

FMX introduced in 1969, used in some passenger cars thru 1985. The only F Series truck to use the FMX were 1973/77 F350's with the 300 I-6.

 

I found a C4 on Maine's Craigslist and picked it up yesterday. It's out of a 66 Mustang and has been sitting for awhile (15 years). I was hoping to find one that had been used recently. I'll have to find a case fill dipstick tube but other than that it's complete with a yoke, converter, and flex plate. I may have to have it rebuilt but I'll try it as is first. I only have 75 bucks in it....thanks to all who contributed to this thread...

The guy also had an old Holley 4bbl carburetor and a couple of good turbo mufflers for 10 bucks so I left with a big silly grin on my face.....

 

Sounds like a good find, Vern. I've got a few extra C4's around here, but didn't mention them because it wouldn't have been worth driving this far for such a common tranny. Heck, the one in my Falcon will be coming out in the next few months in favor of an AOD and it shifts great.

ANYWAYS! A note about that particular transmission that you picked up: the early pre-'67 C4's were referred to as "green dot" Cruise-o-Matics. They had a slightly different shift pattern than what you'll be used to. The pattern is P R N 2-3 D 1. They had a feature in the normal drive position that started off in 2nd and then shifted to 3rd for ice, snow, mud or other low traction situations. Regular Drive with all 3 gears is in the spot where you would normally find 2nd gear. It's not a big deal, but it is an odd little quirk to be aware of. The one in the Falcon is the same way and I forget and put it in 2-3 fairly often after I haven't driven it for awhile. If you buy parts or a rebuild kit, make sure that you spec them for a '64-'66 as there were a couple other minor internal differences between those and the later years.

 

Okay, I'm confused. Since I won't have a shift pattern to refer to...is the first position past neutral where I want to put if if I want it to shift all three gears and is that "2-3" one position or two?

 

For regular Drive with all 3 forward gears, you want to put it in the 2nd detent after neutral - where you would normally find 2nd gear. The 2-3 is just one position. Think of it as drive without first gear. Maybe it will be clearer if I put it this way: (P) (R) (N) (2-3) (D) (1). They only did it that way for the first couple years. Some engineer probably though he had a brilliant idea on his hands. In '67 the shift pattern went to a more standard P R N D 2 1. Unfortunately, the later valve body will not fit into the earlier case, so you're kind of stuck with it. It sounds really strange and awkward at first, but one you get used to pulling the shifter down one more notch than usual, it really isn't a big deal.

 

Personal opinion, that offer for the C4 in FL for 700 is a good deal. TCI really knows how to build them. Throw it on a pallet, it could be in NH for a hundred bucks...

There were so many variations of C4 (TC's, flex plates/ring gears, front pumps, you name it) that buying one that you know exactly what's what is worth a lot.

 

Rage,

Thanks for clearing that up.

Ross,

I'd love to have one of those 700 buck TCI trannys but I can't afford it.

 

I'm not trying to be smart here and understand your way od thinking because I've done it in a number of cases, if you don't change your mind and go with the $75 tranny as opposed $700 one could you tally up the total cost after it's all said and done and post the results back to this thread some time down the road, it could be a learning lesson for when someone else is doing something similar. It could be like the cheap brand tool verses the better brand tool that saved you $10 but it could also be the best deal you ever made. Again I'm not trying to be a smart a$$, I've been there done that

 

Sorry but i sold it.Got 800 for it with the flex plate and yoke.