New to me 2016 F350 DRW

[ticopowell]

Hey all,
I'm about to trade my 2021 F250 with the 7.3 gas motor for a 2016 F350 DRW with the 6.7. It has 118k miles, but the price is better than any other truck I've seen lately. We drove it and didn't have any issues that we could see, just some cosmetic damage.
Does anyone here have experience with the 15-16 trucks?
What should I start with maintenance wise to make it last another few hundred thousand miles? What should i have the dealer do before I purchase? Any other advice?
I plan on using it to tow a 20klb 5th wheel toy hauler.
I want to add air bags for sure, possibly add a tune and an intake. I don't want to delete it right now because I don't know where we will be settling down yet and some places care more about emissions than others.

Let me know what you think
Thanks
Caleb