1968 GT350 Clutch Assembly, 10", 10.4", 11"?

[Corey Bowcutt]

OK so I went to buy the clutch assembly for my 1968 GT350 and of course nothing is easy.  It seems like the 10" is the standard but the 10.4" will bolt right in with no modifications required.  But in order to use an 11" one would have to change the flywheel and bell housing.  What is the common wisdom for the best clutch size to get for the 68 GT350?

[CharlesTurner]

If the car is mostly original, then best to go with the stock clutch size.  Changing out flywheel's wouldn't be too terrible, could throw off engine balance though.  Changing out the bellhousing would be visually noticeable and might create other headaches concerning clutch forks, push pins, Z-bar, etc...

IMHO, the only thing to consider is going with a diaphragm, modern type clutch or the old pressure plate setup.  For driving, you'd probably be better off with a newer style diaphragm.

[shelbydoug]

If the engine is stock, a new flywheel will bolt in and you shouldn't have problems with its balance.

I went to an 11" clutch, a Centerforce dual friction unit. No problems but IF you go to ANYTHING other then the stock then you are going to need to reinforce the z-bar otherwise it will bend on you.

Swapping out the flywheel is no more difficult then changing the pressure plate is.

I don't know if you need to change the stock bellhouse though. I'm using a Lakewood.

[gt350shelb]

If car is  stock  the stock clutch is plenty / I have  been thru a few over the years  and the  longest lasting was the ford  reman (still in the car) and it was the cheapest ........ but I don't know  if they are still available .  there is a clutch rebuilder in indiana  that has rebuilt Alot of  clutches for me

  from  Ferrari & Lamborghini to Duesenberg  they will build to your specs and have been fabulous to deal with  even when building a carbon  kevlar  clutch for the duesenberg indy car  .


http://fortwayneclutch.com/part-category/clutch-friction/

[pbf777]

IMHO, the only thing to consider is going with a diaphragm, modern type clutch or the old pressure plate setup. 

     There are many different clutch release ratios in diaphragms, as there have been different fork ratios for the Long-Style units. This understood, I still have not experienced a diaphragm clutch unit installed in mechanical Z-bar operated Ford vehicle, which presents the proper "feel" in function of the Long-Style units, and I do dislike this "new" experience.

     Scott.

[shelbydoug]

As Phil states, the Ford rebuild is a good one. It has advantages in that it does not put loads on the linkage that was never intended.

It is an organic lining which means it will wear differently and it doesn't like any kind of heat or oil.

It is also rated at 2,600 pound load which is the same as the 6 cylinder engines.

They offered an over the counter "heavy-duty" rebuild that was 2,800 pounds. I've used that and is a good clutch.


Just about any aftermarket clutch is going to be rated at 3,200 pounds. That will twist the z-bar into something you won't recognize.


It's also not just whether or not the engine is stock, but also the tires. If you put a better tire on the car, something has to give. That WILL be the clutch disc. They are not going to take many runs at the drag strip without going away.

Bob Aleberto made 37 runs at the dragstrip one convention in the Hertz car and just killed a tire. I made two and just got the car back onto the trailer with a badly slipping clutch. Mine was a 2800 # Ford.

We could hear the tires squealing but no one realized that they were screaming, "help me, help, me please!" 

[TLea]

IMHO, the only thing to consider is going with a diaphragm, modern type clutch or the old pressure plate setup. 

. This understood, I still have not experienced a diaphragm clutch unit installed in mechanical Z-bar operated Ford vehicle, which presents the proper "feel" in function of the Long-Style units, and I do dislike this "new" experience.

     Scott.

I agree with pedal feel of diaphragm. Hate it    Plus most people don't realize if going with diaphragm you are supposed to remove over center spring on pedal support or you can have dreaded pedal staying on floor

[shelbydoug]

IMHO, the only thing to consider is going with a diaphragm, modern type clutch or the old pressure plate setup. 

. This understood, I still have not experienced a diaphragm clutch unit installed in mechanical Z-bar operated Ford vehicle, which presents the proper "feel" in function of the Long-Style units, and I do dislike this "new" experience.

     Scott.

I agree with pedal feel of diaphragm. Hate it    Plus most people don't realize if going with diaphragm you are supposed to remove over center spring on pedal support or you can have dreaded pedal staying on floor

+1.

You get used to the feel though.

[Steve McDonald Formally known as Mcdonas]

For most drivers the stock setup works great, unless you are really going to race it around the track or drag strip, stock will last forever for most driving

[lalease]

Excuse me for butting in,  :-[Just to be sure, I am replacing my long pressure plate with diaphragm pp. so the heavy clutch pedal assist spring should be removed? everything else is stock.

[shelbydoug]

I think so, yes. I went to a diaphram and the pedal tended to stick on the floor. When I removed the spring it stopped doing that.

[Rocket]

I'm running a diaphram clutch in 6s550, and did not remove the spring under the dash. Been running it for years with no problems. My only problem is that the clutch pedal does not come up all the way when the clutch is released. Ron