I finally got my 4” exhaust hooked up yesterday. WOW, what a difference it made in the old heap. It really woke the truck up. I can’t believe the difference it made on how quickly the truck revs up. I drive it like an old man (of course I am) and usually shift the truck around 2 to 22 thou. Now I can’t stop the thing from reving to 3 before I can move the lever. Been racing and building hot rods all my life and I have never seen an exhaust make so much difference. I have been making up excusses to drive the truck anywhere for anything ever since.. I am a happy camper:hyper:

K&N have high flow but rather poor particulate retention until they get a little dirty then they filter better. AFE makes a better filter in my opinion. just my 2 cents.

Love my 4" turbo back exhaust! Had it straight piped for a while but it was a little loud for daily use, put the straight through muffler on that came with the kit and noticed a little loss of flow, but still sounds mean at WOT and has that awesome CUMMINS idle! This third gen that lives on my road always drives by with his 5" and has me wondering about going bigger in the future though...