I could be wrong but I thought Mustangs had self adjusting clutches and that if you hooked your foot under the pedal and lifted it would adjust itself.
How do you know if a clutch is slipping? If you go WOT in a higher gear, 2nd or 3rd, and the rpm go up, but the tires are not spinning and you are not accelerating, then the clutch is slipping. If you pop the clutch in first and the rpm go up but the back tires do not spin then the clutch is slipping.
My experience has been that a slipping clutch is fairly obvious. Mostly clutches are engaged or not engaged. A slipping clutch is one that is fully engaged but acts like the pedal is half the way down.
the stock setup is infact self adjusting, but it only adjusts the clutch out not down. ( it adjusts the clutch to the top as it needs to, but will not lower the clutch closer to the floor )
ive tryed it. right now my clutch releases at the top, makes for hard shifting. it disengages at the top when i only push it in one inch. i dont have slipping if i run out first and chirp second but if i burn out in first and try to bark second it slips like hell and gives me a horrible clutch smell. in 2.3,,4th gear i can punch it and it pulls and doesnt slip. now ive tryed using the auto adjuster on my car and it only made it release even further to the top
it states to put your foot under the pedal, pull back slightly until it stops, then you have the car off, put it in first gear and slowly push the pedal to the floor and you should hear a clicking noise indicating that it has been adjusted.
also the spec stage one clutch doesnt require anything aftermarket to go along with it. if you go to their website it tells you the spec one is a ' great stock replacement and fits direct with no mods' and also states how the pedal wont be any harder . basicly its gona hold up better than the stock one but feel if not the same then close to it.