hi guys!!!
ecu definetly knows what he is doing with this!!, but I agree, the lingo is quite hard to get a grip of.
preload is just another way of saying that the cable is tight enough to where the clutch fork and throwout bearing are constantly pushing against the pressure plate, enough to put slight pressure on it, but not enough to actually disengage the clutch from the pressure plate and flywheel.
what happens, if you don't have this "preload" is that the throwout bearing is kind of just rattling around there, instead of being planted against the pressure plate. This will cause sqeaking that many complain of that goes away mysteriously when they apply slight pressure. I can't tell you how many people yank their trans and replace the throwout bearing for a squeak that could have been adjusted out!!!!
anyhow, a few years back, I know nothing about preload, etc, and when someone told me to have a couple of inches slack, I thought that meant a LOT of slack, I adjusted it so loose, that caused it to roll forward at the lights, when in first with the clutch pressed. in fact, I kept rolling at the staging line at the drags and was bitching about why the ground at the races was sloped!! Oh sweet ignorance. I wish I knew then what I know now. (and I'll probably be saying the same ten years from now)
The original poster likely still has adjustment issues. by nature the centerforce dual friction is actually such a light effort clutch, that I compare it to the pedal effort of a honda civic, it's actually lighter than a stock mustang clutch. (the counter weights on the pressure plate help with the light pedal effort)
http://50stangs.com/techarticles/clutchcableadjustment.html
here is my take on the whole shebang, and i would suggest the original poster to go over this.
what you've described sounds exactly like a common adjustment problem. Bounce your foot very lightly on the pedal, how much travel does it go before it gets stiffer??? how much "mush" do you have?? I'm willing to bet much more than an inch.
Tighten that adjustment up. In fact, jack you rear up, jack stand it, fire it up, push the clutch to the floor, and stick it in first, leave your feet off the brake. Do your wheels spin??? i bet they do. your clutch is too loose. tighten the adjustment until they stop spinning.
fyi, that adjustable cable IS crap as mentioned already. Ditch it for an oem unit. get it from diversified, mm,possibly 50 resto, maybe d&d for $30-$30, and get yourself a firewall adjuster. If your pedal is stiff at all right now, you've got cable issues.
try the adjustement and we'll all help you from there.