I've always been a fan of the Dynomax Turbo Mufflers to keep noise to a low grumble. They won't be super quiet, but it will keep the neighbors happy and you out of tickets. Just a good, low rumble. You are pushing just about 10-20 HP more than me (minus the NO2), I can tell you that you do NOT want the Flowmaster 40's I have on my car.

I'm 3" all the way out. Believe it or not, they will JUST FIT between the leaf springs and the body panel. It is VERY TIGHT. I'll go get a pic and post it here.

My problem isn't dragging mufflers, it's dragging headers.

I have no idea what the stock muffler length is, never had 'em.