Mike,
After speaking with several people, I believe that the master might have some internal wear, possibly caused at some point by the lack of heat shield coverage. The first time I changed the fluid at 2000 miles it was burnt and nasty. I was told that it turns acidic and could have corroded the "o" rings and caused a lack of pressure. That might have explained why in the past when it got really hot, I would sit a light and the car would slowly start to move forward even when I was standing on the clutch.
After all the work I had done on it, the problems are less noticable, but it was still starting to get hard to get into first.
I think that when the car got hot it burned the fluid causing the slave to go first, but still did less noticable damage to the master. I have moved and coated the lines, change to a DOT 4, non silicone, high temp fluid, changed the slave. Now I will swap out the master, try Bill's new set-up. As everyone said, I have a standard Ford 392 crate motor, TKO 500, traditional bell housing. Basically, I will have replaced almost the whole system;
New lines, new fluids, new slave, new master, moved and coated the lines...
If this doesn't work, maybe I'll buy an new ZR1 with a warranty. Naaa! The Cobra just looks too good.