Upper pulley swap question

[George G.]

I'm thinking about swapping my upper pulley for a stock L pulley. Is it possible to change these pulleys and leave no indication that it's been swapped? Or does it usually leave some markings. I want to get more boost but not risk voiding my warranty. Thanks for any info.

[L8 APEX]

You usually leave a few marks on the pulleys. I owuld just do the lower if it were mine. I remove the blower snout and change them on a press not on the truck.