did these come as 10.5 or 11 inch?

thanks,

Chris

stock is a 11 but GM offered a nodular iron performance one and it was a 10 ½.

any advantages to using 1 over the other in a 400hp application?

do I need a specific bellhousing / flywheel etc based on the size?

any advantages to using 1 over the other in a 400hp application?

do I need a specific bellhousing / flywheel etc based on the size?

The bigger the clutch, the more surface area for contact, the more durable it will be.
Yes, there are two different setups, with the 11 inch clutch you'll need a 621 bellhousing, the 14 3/4" flywheel, and an 11" clutch and pressure plate. With a 10.5, you'll need a 404 or similar bellhousing, and the corresponding parts. Starter nose will be different too.

Great. Thanks a lot!

11" it is!

Chris, did you change your mind again about going back to a more stock appearance?

Chris, did you change your mind again about going back to a more stock appearance?

who me? I never change my mind!!!!!

What was I thinking?:D

In '69 you could order a h.d clutch, rpo MA6. It replaced the single 11" disk witha pair of 10" disks working together in tandem. By having 2 work together, neither one works too hard. They were able to run them with half the pressure plate pressure, making for light clutch pedal action and again softening the environment that the clutches work in. They also had greater area together, plus each disk being 10" (each disk has lower rotational mass to explode) and only shouldering half the load, you now have an explosion-proof clutch. Very trick. It was an obscure option on '69 Chevelles and other Chevies, from the 300-horse 350 upwards (plus the Z28 302).

The aftermarket offers one like it, the Dualforce.