9" and 9-1/2" Clutch and Pressure Plate Questions

[rhpope]

My questions are about the comparison between the 9" and the 9-1/2" clutches

The 9" clutch is just the typical clutch that was used for many years that used a standard Long style pressure plate. See the link.

https://fortwayneclutch.com/product/...ew-sku-kt5102/


For the 9-1/2" clutch, the pressure plate looks different than a standard Long pressure plate, but it still appears very similar. See the link.

https://fortwayneclutch.com/product/...t8594-1-375_r/


My questions are these:

Will the two interchange on the same flywheel or is there a difference in pressure plate bolt pattern?

What are the bolt circle dimensions on the two different pressure plates?

I have a 9-1/2" pressure plate that I measured the center line of the bolt circle to be approximately 10-7/8". I do not have a 9" pressure plate to measure the bolt circle. Is the 9" approximately 1/2" in diameter smaller?

Is it flywheel specific and would have to be redrilled if changing the size of the clutch and pressure plate between 9" and 9-1/2"?




Thanks for any help,
Roger