I know that swapping the SC pulley is SUPER common, but I don't know if anyone has experienced any trouble with the drivetrain after doing it. I can't imagine it would cause any problems.

I seriously doubt it added 40 - 50 horses though. A buddy of mine swapped the pulley on his supercharged Mustang GT and it only added around 30 horses, and he had 300 to start with. You maybe got 20 - 30 horses out of the pulley and intake. That's still respectable though!