I'm thinking about getting a few PAL 2600 games and don't know if they will work on my NTSC 2600. What should I do if PAL ones don't work?
It's usually not a problem with the 2600. It a problem with your TV set.
Older TVs & even some old monitors like the Commodore 1702 would allow some adjustment to the v hold, I've used the old Commie monitor in the past to play PAL carts.
Unlike almost any other console, the region of the 2600 game determines the output format not the console itself.