Okay so I just finished the restoration on my dart and I've been have problems with shifting. I can't down shift without it grinding, can't put it into second with it popping out or grinding and if I shift to fast it grinds when I put it into gear. The z bar is also rubbing on the starter, I'm in need of help. Everything is stock on the car. Here a pic of all the pieces for the clutch linkage

Another view of z bar

You need to remove the bellhousing dust cover and check the clutch disc air gap with the pedal fully depressed.

I had a similar issue and it ended up being the shifter box itself being worn out. You have a series of trial and error issues.

If it grinds, you either have bad syncros or the clutch needs more air gap. I'd adjust the air gap first, as it don't cost anything. Another possibility is that the pilot bushing is too tight......

what part is wrong/misadjusted that the zbar is rubbing? that'd be the first thing I'd resolve (then air gap) & I'd think the zbar prob would be skewing the air gap

If you are using a McCleod pressure plate it could cause some of those problems. It seems they had a design flaw. I bought mine in a conversion kit, they sent me a newer design and all is well.