Cab Resonance!!

[88Vic]

Put tailpipes on in. When I took mine off, even my 24" case Magnaflow droned. Now I have an 18" case but it's exiting out the side. The turndowns bouncing the exhaust off the ground to the underside of the truck and back and forth will create than drone. Just turning the turndowns sideways and extending them out the side will help, and tails out the very back will likely eliminate the drone enough to wear you won't hear it inside.

[Turk09]

Originally Posted by Outlawz2004

extend those turndowns past the rear axle and that will help. Swapping that flowmaster will really help. I have longtubes, no cats and slp loudmouths with no drone, dumped just over the rear axle.

I went the magnaflow catback route on a Ford ranger before getting this new chevy. Yes, it was almost a OEM replacement, complete with the single side exit behind the right rear wheel.
The drone inside the cab drove me nuts as well!!! Almost had it removed after only a week!! Took almost 5 months to mellow out, but still was there at 45 mph. I guess your going to have to get a system that's setup to be quieter from the start!!

[SteppinLo]

I have a Magnaflow cat back with no cats and I have drone. It has a single, four inch tailpipe out the back at an angle.

At about 2 thousand rpm cruising it is ruff. I hit tow/haul and it down shifts or I speed up to get away from that rpm/load level.