[vector1]

i have a few of the different designs on the jbl and here is my experience.

one set had the holes inside the muffler, another had the inverted fish scale look, there was a difference in sound with the holes being slightly louder, but not what i would call significant.

would be my opinion to use something with the largest internal diameter cause it's going to be loud no matter the design. also depends on where the outlets are pointed but be careful, if you point them down it can raise a pretty good dust cloud, to the side breaks the db level. both my engines are low compression and neither is terribly loud.

on one of mine i set the muffler up so it sits in a craddle with two springs holding it in, i can switch it out with a straight pipe by loosening the v-band clamp on the entry and removing the two springs, about a 10 minute ordeal.

sent you a pm also.