I had a FM40 Installed (3" In, 2 1/4 Dual Out). All I have to say is DAMN! I sounds mean. I start my truck up, or even just driving by and I'm setting off car alarms! I ended up having the tips (SS Chrome) come out at 45 degrees. My friend wants his done now (It's not an Av....it's a Jeep, so if isn't as cool)! I'm going to try and get it on my dad's lift sometime soon and take some pics of the underside.