clutch size

[charter]

I called the local auto parts store and ordered a clutch for a 68 F-250 4x4 FE390 NP 435 . I got it home and it was to big ( 11 1/2" ) for the 11" flywheel bolt pattern. The parts guy had to
get a 11 inch clutch for a 68 F-150 FE390. Should I be concerned ? Is the smaller clutch due to an engine swap that was done before I got the truck ? How well will the smaller clutch hold up when towing a slide on 9FT camper and pulling a 17FT boat ? The FE390 has been rebuilt for high torque. Comp cam 33-224, Edelbrock top end ported polished, Edelbrock 650 carb, MSD ign., hedman 1 7/8" headers, 2 1/2" exhaust with a cross over.

[fireguywtc]

This biggest clutch I could ever find was 11 1/2 inch for an FE. If you can't find one, I think 11 would be about as good. How big is the one you got? Did you measure it?

[charter]

The parts book shows an 11 1/2" for an F250. An 11" for the F150. My flywheel bolt pattern is for the 11" clutch. Did ford use an 11" clutch in the 250's ? The pressure plate of the 11 1/2' is much larger, has three fingers and bigger springs. Are there different bell housings to handle the different clutch sizes ? I have three flywheels and all three are for the 11" clutch. I picked up a 76 F250 for the chassis. It had a 390 with the 11" clutch just like my 68 F250 390 ( 390 out of a T-bird ). Should I get a flywheel for the 11 1/2" clutch for the larger torque FT. Lbs. ?

[robroy]

Good evening Charter,

I was in this exact same situation a few years ago; I bought a clutch, but the bolt holes in my flywheel were smaller than the new pressure plate's.

I then learned that FE Bumpsides came equipped with two different (but very similar) clutch sizes, and my truck ('72 F250) had the smaller of the two.

I wound up buying a new Centerforce 700260 flywheel to fit the larger clutch.

Maybe you'd like to skim through this thread:

Flywheel for 12" Centerforce clutch (DF200015).

Robroy

[charter]

Thanx, robroy however you and I are working on the opposite sides of the spectrum. I'm sure the clutch, flywheel you have is way more than I need for my torque range. I just want to make sure that the one ( 11" ) I have will do the job or will I need to get the stock 11 1/2" clutch. I just found it alarming that the 11" is in F-250 when the parts book lists the 11 1/2" clutch to be the correct size used from factory. It may not even matter. But I'd rather find out now than have to call a tow truck because the clutch wasn't the right one to handle the weight I'm towing through PA and NY mountains