To adjust it, I loosened all the turnbuckles and put a drill bit into a hole to lock the main pivot arm in place. With the arm locked, I adjusted the first turnbuckle to take the slack out of the cable, which also raises the pedal. Then I adjusted the other turnbuckle, to provide just enough slack so that the throwout bearing does not contact the pressure plate when the clutch is disengaged. It's actually a pretty slick system for adjustment. It took me a while to do all this because I wanted to make sure I was doing it right. Next, I'll put oil back in the transmission and reattach the last few pieces to finish off this job.
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In case anyone is wondering on the exact adjustment procedure, there is a very good writeup on F-Chat. This procedure is only for the early 308 clutch as the later ones have a different linkage configuration.