Hey guys. I been trying to understand why my F350 is so load, my buddy has an F250 with the same 6.0 and his has way less cabin noise. Will after going through the problem I hit it on the head. I was the dame shift boot. 3 of the plastic legs broke and the noise would just come right in the cab, Here is how I fixed a problem with out getting a new boot. Just a longer screw and a washer, the rubber covers the evidence.