Okay another newbie forumer here. I'm looking for some input on the same topic. I'm going down to a custom exhaust shop tomorrow to get a cat back duel exhaust put on. I have a '11 5.3 V8 silverado 1500. The exhaust place carries magnaflow and flowmaster mufflers so I have to make a decision. Someone suggested the 40 series which sounded decent when I heard it. I'm looking for a deep tone, minimal cab drone, and little crackling. For the tips I think I've already decided to go with the 4" black chrome tips, exiting behind the tire, similar to oem location. Any suggestions/recommendations on my setup? If I should have created a new thread versus replying to this one let me know...I'll def. have to read over the rules this weekend.