There is a fair amount of preload on the clutch cable. Tighten it up and as long as 2nd gear upshift gets good rubber, you are OK. That works OK with a Tremec 3350, but maybe not so good with a T5.I did try to put a turn or 2 on the adjuster when i got to work, the cable is tight. tighter than i think it should be.
OR spare the fragile T5 and try this trick...
If the clutch slips when you put it in 5th gear and floor it, then the cable is too tight