Quote Originally Posted by Gusaroo
Well I am aware of the balanced flywheel, and my 454 is out of a truck, so I am hoping to stick with the 12" setup I had (mostly just to save me the expense of purchasing a new flywheel). As I started shopping thru the catalogs and online for a 12" clutch and Press Plate, I am noticing that most don't specify whether it is BB or SB. Which leads me to think they are interchangeable, hence my question.


As far as the diameter of the clutch vs actual surface area grabbing, follow me on this thought. If the clutch surface area is futher from the center of the flywheel, less force or surface is needed, correct?
That's correct. The torque the clutch can manage is mu*F*r or mu*P*A*r where mu is the friction coefficient, F the mormal force, P the pressure and A is the area, and r is the radius to the center of the clutch pads. Since r is larger on the 12" clutch, then A can be smaller and get the same torque results.

Kitz