Thanks everyone.
Here's what I did.
Pulled the z-bar out and greased the hell out of it (again), and lubricated both clutch pedal rod and gromet opening at firewall.
Replaced the clutch return spring that came in the new z-bar kit with one that matched the looks in the Pontiac service manual. Easy to get once I knew what it was.
It was clearly heavier. Clutch pedal pops right up now.
Rubber clutch bumper stop I purchased from Ames was just over 1" tall. I shaved it down to 1/8" and pedals line up perfectly.
Clutch adjustment easy, drives perfect with new 4 speed.
Thank you all !