When installing baffles into 2″ shotgun Harley pipes, how deep should they be from the end of the pipe?
Bub pipes don't have a pre-drilled hole for baffles. I'm guessing about 1-1 1/2 inch.
While loud pipes save lives and sound good, you need the back pressure for performance. Without baffles, you loose 5-10% HP; carbon up the ends of your pipes & don't burn fuel efficiently causing the 'pop'/flames out of your pipes. Baffles cut down the noise only about 5 decibels & cops leave ya alone if they can verify you have them in your exhaust.
There really is no spec for this, but in general, most everyone drills the hole about 4" from the end of the pipe, just make sure the hole is drilled the same distance from the end on both pipes. Use a pair of needle nose pliers to hold the nut inside the pipe while starting the bolt and then you can switch to a wrench to tighten it up.
Just out of sight would be fine.
Why would you want to put baffles in the pipes anyway?