The creaking isn't from the body mount itself, its contact between the top bracket and floor pan itself. That being said if you plan on doing the TSB, I would do that before foaming stuff. It wouldn't affect changing the body mount but you're better off not having the cavity filled with foam before they go to work on it. Most of the guys with the creak still have it after doing the TSB so I didn't even bother doing it. Pretty sure I know how to fix the creak but it's going to take quite a bit of work. So I opted for the 10 minute fix and used a couple cans of spray foam it's only been a day but so far I can't hear the squeak, creak or whatever you want to call it while in the cab.