exhaust

hey i am having trouble finding a flowmaster muffler to fit my 06 silverado reg cab z71 lt 1500. dont want to do a cat back was planning on just replacing the muffler even dont have the money right now to do a cat back so was wondeirnf if anyone foudn a site where i would get one or knew the measurements of the inlet and outlet so i can order one thanx

2 1/2 inch all the way isnt it?im pretty sure mine was on my truck.

mines also 2 1/2 all the way