Putting a 4500 tank regulator on a 3000 tank

[MuKen]

Am I correct in guessing the only thing you have to change is to swap out the burst disk so you'll know if the tank is getting too far past 3000?

[Chuck E Ducky]

Yes perfectly safe just swap out the Burst disks just so someone dose not accidentally over fill it.

[Flounder]

Maybe add a little sticker over the 4500 on the reg to say 3000

[XEMON]

Maybe add a little sticker over the 4500 on the reg to say 3000

That's an often overlooked advise!
mark stuff like that so:
1) you remember in 6 month, a year or 10 years from now
2) someone pick it up and know what's going on