I am going to install some new exhaust on my 2000 1 ton and, I just want to know if there is anoticable difference in performance between 4 inch and 5 inch exhaust...also, the exhuast will run straight through (no muffler) only modifications are an air box and programmer.

 

unless you plan on puttin on lots of power just stick wit 4"

 

4" is good for around 550-600hp