Went with cat back Flowmaster 40 single. sounds pretty good. Am still a little concerned about sounding like a bumblebee with the 6 cyl. but so far it's OK. Going on a long trip tomorrow. So I guess i'll find out if it's to loud for me then. ( only drove a few miles since the install ). Wanted to go with the 50, but the owner of this shop recomended the 40 for a single pipe (2.5" in & out ). Said if I thought it was to lound in a few days he would swap it out with a 50....... so i thought I would give it a try......seams there is nothing to loose.

 

keep us posted. I soon hope to get a 40 series delta series flowmaster on my 4.2.

 

Not to loud..............but sounds good when you give it some gas.
put 500 miles on it Wednesday. does seam to drone a little in 5th about 80mph.