On my 72 Cutlass, I replaced some really crappy door handle mechanisms on both sides as there was a lot of play in splined portion. The passenger side door opens freely from the inside, but you have to literally yank on the inner handle to open the door. When the handle is pressed from the outside the door opens immediately. I'm assuming the door latch should be next? If so, is there one vendor over another that has a better quality part?

 

It could be the linkage is bent/stretched. I think the latch operates the same whether it is activated by the interior handle or the exterior handle, so the difference in operation could be due to the linkage rods.

 

Thanks, I'll pull the latch out when I get home to see if it looks bent.