13 SG with stage 4, Rush True Duals, Big Louie 2 in. baffles. When I installed the stage 4 the 259 cams really woke the Big Louies. Too much for my 59 yo ears. Need to quiet it down, planning on putting my stock mufflers back on. How will this effect HP/Torque? Am getting it retuned. Suppose it will be difficult to tune? May try some different mufflers but am starting with the stock since I have them.