Reply to "New Clutch"

Pantera Performance in Castle Rock, CO sells a "centerforce style" clutch that works with your stock flywheel. I've been happy with mine.
Don't be tempted to use a Mustang clutch out of a catalog. There is something different about the Pantera flywheel thickness (if I remember right) that makes the stock 351C clutch work poorly. You'd hate to have to re-pull the ZF and buy a second clutch just to save $100 on the first one!
While you're in there, be sure to consider buying a new pilot bushing. Try to find one that is a real oilite bushing. The ones you get at the auto parts store tend to have a lot of steel content and can seize up. A magnet will actually be attracted to them! I wouldn't use a needle bearing. Great for racing where you're going to replace it periodically, but for a street car, I'd choose a long lasting original style.
I think Marlin Jack, who frequents this board, makes (or knows where to get) the good ones. You might contact him for advice on a new pilot bushing.
Mooso