I have the Diamond eye system with a straight thru design muffler.(no louvers)With the straight thru muffler it is really not that loud. I would just install the thing the way it is supposed to be and not worry about the sound level.Unless you are running covert operations at night where absolute silence is a must. Oh but then your up a creek anyway because its a diesel.LOL 
__________________ 06 2500 CREW CAB 4X4 LBZ
4" DIAMOND EYE EXHAUST, KITTY RAN OFF!!!
DIABLO @ 120HP. 285/75 BFG's RUNNIN ON ULTRA 16's
PIONEER HEAD UNIT RUNNIN SCOSCHE AMP W MTX TWINS
AIR BOX IMPELLER REMOVED!! RESONATOR PLUGGED !!!
AUTOMETER ULTRALITE GAUGES IN POD. TRANSGO JR  WORK RIG
O7.5 3500 CREW, LMM, ROYAL UTILITY BED
4" DIAMOND EYE EXHAUST.DPF???KITTY?? QUADZILLA PROGRAMMER. MTX AMP AND 10" TWINS IN THE BACK. STEPS,VISORS,BUG SHEILD. AIRBOX IMPELLER REMOVED,RESONATOR PLUGGED,LOTS OF PRETTY DIAMOND PLATE EVERYWHERE  |