Okay, I tried to reply earlier and lost power at the computer....what a master piece too. Now I will condense to answer Denny's question. So many flywheels have been offerd for the mulitiple bolt hole applications for varied size clutches. The flywheel does not grow; only the surface area and offerings of bolt patterns to allow your choice in clutch. My original post in this thread was to enlighten the fact to those who wish to read, was the fact that a 12" clutch can suffer mating and apply surfaces because of the manufacturer. I can run an 11" clutch with more grip than some 12 inchers. Solely because the outer diameter may be 12 but the inner diameter is a mere 10.5. Where I can use a 9" I.D. to apply more frictional surface maintanig the O.D. of the 12 I was trying to achieve. Sometimes a smaller clutch can have more total area than a large one. My point was merely to explain that a 12 is not always a 12 because it will be worthless if the builder does not see that the unit is as weak as a 9, a 10, an 11, etc. Look and measure. Bigger is not always better. If you can score a good unit with large frictional area, run the darn thing and don't look back.