hello just received new parts for supertrapp  pipe disc  x 12 end cap with 1" 1/2 hole. can  i open the hole out to 2" before i install it  .? is there a reason for this size hole.? installing on 2004  v/twin fatboy.thanks  

thanks dave for info. i will leave as is   and see how i go first time for oringal end cap. might be the sound i want thanks. cheers.

thanks again wozza for your advice. i will try the new end cap  the way it come . it might sound different altogether being a icecream cone shape.thanks. cheers