i have a 05 2500hd 6.0L and i am wondering what you would recommend. i am going to be running True duals and dumps. i was thinking of running 2 super 40 flows but i dont know if i want it to be that loud in the cab. Can anyone recommend a good loud muffle? I was also thinking of running 2 SLP loud mouth 2s with dumps but i dont know how that would sound. Spintech mufflers any good or loud?