I think that is what is on my truck, bought it this way but could also be one of the 40 series. But it is loud, I like it but the wife doesn't she is always telling me that we are going to get pulled over in it. She did get pulled over for it once and his excuse was it had one of the third light bulbs out, but i figure it was for either the exhaust or he thought the side windows were tinted. Mine right now is just the factory manifolds and starting at the crossover 3 inches all the way back and exits behind rear tire. You can hear it going down the road about a mile away.
One thing is if you go 3 inches you might have to increase the length of the mounting rods, the guy I got it from didn't and it is right against the cab and rattles becuase of this. Plans are to hopefully fix this the summer as it gets really annoying, especially at lower speeds and going through camprounds.