Correct size clutch for a 390?

[TrevorK]

Can someone confirm what is the correct size clutch for a 390 Mustang? I've seen references to both 11 inch and 11 1/2 inch. Thanks guys.

[22GT]

IIRC, the 67 was 11.5", thereafter 11".

[TrevorK]

Thanks - I see that the 67 shop manual lists a 11.5 inch as being correct. I'm a bit confused as to what I have - The car came with a big input toploader when I bought it. The big input clutch plate that was used was only 11 inches, so the wear pattern on the flywheel is this size (any issues with going to an 11 1/2 clutch and not resurfacing the flywheel?).

My bellhousing is C60A-6394-D, which I believe is correct for a 67 with the 390 (and for an 11 1/2 inch clutch). Is there a difference between 11 inch and 11 1/2 flywheels?

I'm thinking it's probably simpler to just stick with the ll inch clutch, even if it is not 100% correct...

[gregb]

I don't think the 11.5 inch pressure plate will bolt on to a flywheel made for an 11 inch clutch. I used to see the 11 inch disc used with the 11.5 inch pressure plate when I worked at a parts store way back when, think it was because the 11 inch stuff was commonto a lot of stuff and the 11.5 inch was not, so people in a hurry just changed the disc out. It isn't right, but works nonetheless.

[TrevorK]

So it looks like I have a flywheel for an 11 inch clutch. Are there any issues in using this flywheel with my original bellhousing that is made for an 11.5 inch disc (i.e. the starter gears lining up with a smaller flywheel?)

[JDM4401]

I don't believe the flywheel is smaller, the bolt pattern is different from a 11.5" to 11". The diameter for the flywheels shold be the same.