is the c4 and automatic or manual??? i have a friend with a mustang and he has a c4, its a 4 speed manual. ive also seen c4's that are automatic. is it just the shift kit that makes the difference or do you have to buy a specific c4 manual? i want to shift the damn thing but i dont get it. please help, any information is appreciated.
thanks

 

The C4 is a 3 speed automatic. Your friends 4 speed mustang does NOT have a C4

 

so now im really confused, i know there were four speed trannies for 67-72 mustangs. the only reason i want one from one of those years is because i have a 351C in my 67. i just need a four speed something that can handle around 425hp without dropping the thing. that and i dont want to lose any horsepower because of a huge trans. it would also be nice if it would bolt right up to my engine. thanks for the clear up on that one though, ive been thinking backwards for a few years now!

 

I think what you are looking for would be a toploader.

 

I had this big long thing going but it didn't take. Anyway, back to your basic question. Do you want a 4 speed manual? (answer-toploader).


Or do you want a 4 speed automatic? (answer for 351 c is probably C6 with aftermarket OD)

Or do you want some dragstrip special like an automatic with a clutch in front of it with a manual valve body? (it's going to be a 3 speed if it is from Ford parts)

 

id love to get some kind of toploader obviously but have no idea what would match up to a 351C and at that, ive heard from some other people that the C6 eats up about 60 horse, and i really dont want that. what about the tremec 3550? a lot of places sell those but i dont know how reliable they are and what not. basically then my question is what 4 speed toploader would be the best to match to my 351, without eating up too much horsepower? thanks for all the information though, its been helpful

 

Since you have two threads running on this topic, I am confused. Do you have an automatic now?

Is there a clutch in pedal in the car, or was there ever one? Or do you have the big brake pedal only?

If the car was built as an automatic, putting clutch linkage in is a major pain.

Plus, with the values of fastbacks going thru the roof, consider keeping modifications reversable

Do you want an automatic or a manual? There are losses involved in any transmission. Some are better than others.

If you want a manual and go with a toploader, you have a choice of close ratio or wide ratio. CR for bigblocks, WR for small. Your 351 would handle either, depending on what you want to do.

But you have to decide which way to go. Auto or manual. Period.

 

I converted my 67 fb to manual and really wasnt too much trouble. I only did it because the previous idiot (owner) butchered the factory console and shifter and was able to get a manual one. As to the original post the c4 is an automatic 3sp.

 

ok i have an fmx 3 speed automatic. its just been rebuilt about 800 miles ago. there is no clutch pedal in the car, and it is the big brake pedal only. the door isnt original so the door tag information is obviously innacurate according to the rest of the car. what problems will be presented when trying to put new clutch linkage in the car because of it being and automatic? i know there will be but what specifically... this car is going to be a father son project, as my dad and me have always wanted to do this and finally are going to. my dad used to be an autobody mechanic, but doesnt know too much about engines and trasmissions so thats why i come here. im not worried about keeping it original beucase its never going to be sold, we want it a little different from everyone else's original fastbacks.
i would like to get a manual 4 speed, i want to be able to shift the car, i think it will make the car much more fun to drive, but still dont know what one to get. i dont want to lose power by getting the wrong tranny, but it seems the fmx pulls it down a little more than a 4 speed would. i also know that the 351C is considered a big block, so what do you think would be better for a new toploader? (as in wide ratio or close ratio)
thanks for all the input

 

IMO, I would stick with an automatic.

First, you have several mods to do to convert to a clutch. Underdash work, linkage work, z-bar etc. Again, IMO, the clutch linkages in the eary Mustangs left much to be desired.

Second, you are going to have to come up with a clutch set up. If you do this wrong, you can blow up the clutch. If you do it really wrong, you can cut the car in two with the exploding parts. Not likely, but possible. If you are going to race it, you need a heavy scattershield bell housing. Your clutch explosions, if any, will be confined to the bell housing then.

I say this because you are going to be working the a mix of parts, not a list of parts out of a book for this model/engine/trans and since you say you are limited in experience on the engine/trans mechanical.

Next, let's go out back. Did the car start with 289/302 or a 390? If you have an 8" rear end, say goodbye the first time you drop that clutch. Even a 9" needs traction bars and/or beefing, as the Mustang leaf springs will wind up and hop and put on quite a show in stock configuration. I added a leaf to mine, but I just had a 289. Improved the ride, brought the rear up 2", helped with wind up.

Anyway, just my opinion. I guess what I'm trying to say is sort out, tune up and improve what you've got, cause it should run pretty good--.

Now if you must do the 4 speed, the close ratio is seen as the "hot set up". 1st is a little tall, but so what? If you drag race, you are going to want 4.11's. If you road race, well, you aren't going to be in 1st much anyway. You may want to consider a 5 gear, check this site, folks are talking about a new Tremec. Overdrive, you know. Good luck

 

so...i hate my fmx tranny. its new, but feels like im losing a lot of power because its only a 3 speed and it could jump a lot quicker if i had a 4 speed. the rear end is a brand new 9 inch, so i hope i wouldnt have to worry about that. i think??? im not planning on racing in any aspect, but i do want to have the available power to do whatever i want with. the original engine was definitely a 289, with an automatic. i wasnt planning on putting the tranny in by myself, but how much would it cost to convert if i got it professionally done?

the expirience thing...ive never done it before, thats what i meant, even though ive researched it much over the past few years. i still dont know exactly what im doing though.

i have leaf springs that sit almost all the way out to the rear valance, so i dont think that would be a problem. but again i dont know. it sits pretty tall how it is.

ive looked all over the tremec website looking at the 5 speed 3550. it seems like a good transmission that would be able to handle the tourque of my engine. (rated at 450 lb ft. i would hope it will be enough) i would like to get this but at that, what conversion kits would i need to get to match it up to my 351C?

thanks for the input again, i appreciate the info.

 

The cleveland has the same bell as the windsor motors 289,302 351. Are you sure your motor is a cleve and not a modified? if it is than Iwould get rid of it and get a 289/302 then you can buy all the clutch parts you meed. If it is a c then you might have to fabricate the equalizer shaft and rods for it but pedals can be bought at Mustang suppliers. I was running a 4sp toploader but pulled it when the countershaft bearings hung up and put in a toplader 3sp the car is much quicker with the 3sp so 14 years later its still in there. Take your time and use good parts and it will be plenty reliable. Oh BTW the starter is different for manual trannies.
Quig

 

i know for sure that my engine is a cleveland. it only has 800 miles on it and i dont really want to swap engines, only because i know this one will be reliable because it was professionally built. i have no idea what an equalizer shaft is as well as rods for a tranny. i know nothing about how transmissions work. if i was to get it professionally installed, how much do you think it would cost to have one done? what do you think of the tremec 3550? im thinking about that one because ive heard its the one to get. thanks for the info.