264*/272* @ .050, 106* LS, .690/.666 Lift...now that's a spicy meatball!!! A non-carbon button clutch really can't take any slipping. They heat up quickly. A 7.25 will be much better than a 5.5" or 4.5" though. In any case, they are all unsprung. With the 5.5" clutches in oval racing, the rule of them is they get virtually all their wear in the paddock.
What people have done in the Supra and I believe Evo communities is use carbon clutches. These are really light. However, they can take an incredible amount of slipping. Depending on the manufacturer, when hot some become very grabby. Too grabby for driving in traffic. Others, I believe including Tilton, are still managable.
The typical setup in those environment is to use an OE diameter clutch with a double or triple disc 7.25" carbon clutch. Sometimes the outer part of the flywheel is not solid.
Does the car idle ok with the light setup, or did you need to raise the idle?
Thanks,
David
P.S.
What valve spring and rocker setup do you use?