You should start that dlc at lvl 72 if you have all the level caps so you can wreak people when farming and you can use those great guns from your patience for OP levels. I recommend starting the dlcs that have guns that you want that are in onley the dlcs. Ned to Moxxis Heist of the Handsome Jackpot, we rank every piece of DLC content released in the Borderlands franchise. When you get to UVHM (Ultimate Valt Hunter Mode) you have to choose wisely with your docs because you want the good loot. It's your choice if you want awesome loot in the begining of the game or awesome loot at the ending of the game so you can pass through you're next game mode with ease. In UVHM (ultimate valt hunter mode) you can start a doc that you want to be your level from level 35 to 50. Then go into the dlc's in playthrough 2 mode Moxxi, Knoxx, Zed, then Claptrap. At a story point very near the end of playthrough 2 the game will enable a universal scaling to the enemies to keep them around your level. In normal mode you can start the docs to your lvl at level 15 to 30 accept tiny Tina's assault on dragon keep and hammerlocks big game hunt which is level 32 to 35. Playthrough 2 stick with story missions as much as possible, only do side quests to keep your level even with the main quest level.

Borderlands 1 dlc quest levels