Three on the Tree losing 1st

75 Duster slant six 3 speed on the column. Not sure if I have a A230 or A903. Every once in a while, when shifting into 1st, the transmission would sometimes grind and not go into gear, and would sometimes rarely pop out of gear. Driving recently, the trans popped out of gear more harshly than usual, and now I have to rev it out way more to get into 1st, and after shifting and letting out the clutch it seems somewhat rough. Is my synchro going bad? Do i need a linkage adjustment? could something inside the column be wrong? What do you guys think?