I have a 71 240z that I’ve recently got driving again. It was having some trouble going into gear so I changed out the clutch master and slave cylinder. Now the car has no problem shifting up but seems to not want to shift down easily and grinds when I try to put it in reverse. Any thoughts? I’ve attached a video that shows the slave cylinder actuating when the clutch is engaged. Do I need to adjust the slave cylinder to actuate farther? When the clutch is pressed engine goes into neutral fine.

Did you follow the instructions? Don't know why they show the measurement since most people will just tighten until play is gone and loosen 1.5 turns. Nobody's going to stick a feeler gauge in that hole. Don't forget to bleed.