Clutch Chatter? 1970 4 speed

[farmallboy15]

First off the truck is a '70 GMC K2500. 350 sm465 np205 setup. I've been through most of the truck just not trans and t-case. I believe them to be original, no rebuilds. Engine is a crate that was put in in the 80's. Truck has 80,000 miles. Engine about 20,000. I'm assuming they put a clutch in when the engine was done...? There wasn't any real gunk in the clutch area when I had dropped the inspection plate.

My problem is a real bad hopping when starting in 1st and reverse when trying to feather the clutch. It was pretty smooth when cold. But as it runs, like a half hour it gets pretty bad. I think the clutch is releasing in the top third of pedal travel (i'll have to check again).

Is there any adjustment that would help me out or should I just be looking for a clutch? Now I have it an hour away at college with lots of stop and go traffic and parking... Thanks ahead of time!