Performance clutch?
I don't know for sure but I imagine the flywheel is drilled for a 9.5" clutch. Brewers has a 10" conversion clutch that works on the 9.5 flywheel. Measure and ask questions to be sure. That pressure plate can be modified for more clamping force. The local Clutchmasters can help you too. They can modify and even change the disc from organic to metallic or even ceramic lining.
http://www.brewersperformance.com/products.asp?cat=251
tmm