I saw that eBay seller.  But do these pins give any greater functionally than the Dorman pins that are 4 times less money?

I've not used either so I really can't say for sure, but my guess would be probably not. The sizing might be a little different.

I wish I could remember where I bought mine, but the kit in the pic looks like what I bought.  They really worked good and definitely no more door sag.

Maybe a bit late to the party but I’ll be using this thread to rebuild my 1977 280z door hinges as the passenger side in particular sages so much that the door won’t even close anymore. Any tips on removing and installing the doors on a 280z? The tricky bit is that they are bolted from the outside and I don’t want to remove the entire front end.

Do they not bolt from the inside out?

No as far as I know with the introduction of fuel injection they switched from inside to outside as they where in the way of the ECU and fuse panel.

Pictures would be good. You can probably get a view from inside the open door, towards the front. If they bolt from the outside in, the fenders will need to come off unless you don't value your paint...

They have a hinge mount plate on the inside that will fall when the bolts are removed.

If they fall down can you still get them back up into position? I saw a guy on youtube that unbolted the hinge on the door side first and after the got the car side with a wrench and swivel sockets.

I might try to go that route as the car doesn’t fit in the garage (and still work on it, only 2m wide for the first 4 meters). I do have a lager carport where I park the car under to work on it so the car is still dry. That does mean I’ll have to cover the car if I take the doors off but I had to do that anyway.