The reason I asked is ride height adjustment on Monsters, except S*R models, does not change the distance to the pegs. It will change the distance to the ground. I believe you have a hoop from the shock linkage to the swingarm. At the bottom there are two heim joints threaded into the hoop.
Lift the rear of the bike, remove the bolts, loosen the locknuts, and turn the joints out the same number of turns. You need to leave a safe amount of threads in the hoop. The ride height will increase more than the amount you move the joints because of the linkage ratio.
This adjustment will change the steering geometry and make the bike turn quicker. Be prepared when you first ride it.
If you want to give yourself more room to the pegs you'll have to get aftermarket rearsets.