Clutch linkage adjustments

[71rehab]

I've searched the forums but haven't found exactly what I'm looking for.

Just took delivery of a 71 C20 4 speed manual with 55k miles. I must push the pedal to the floor for engagement and I can't even get it to engage into reverse without a harsh grind. Sometimes I get a smooth 2-4 gears.

I looked at the linkage adjustment in the manual and the nuts are already at the far end of the rod. Under the dash there appears to be some slop between the push rod and the pedal assembly but nothing too bad.

What are my next steps? Am I missing something? Am I probably looking at a worn clutch? Any other tests?

Thanks!