I am having a birthday on Saturday....and told the wife I wanted a new muffler for my 04' FX4. I am spun on which one to get. I don't want a crazy loud exhaust, that cracks & pops. Don't want drone in the cab. I know I want to go w/ Magnaflow. I have read that guys like the 24". But I also read that it isn't much louder than stock. But I also read that the 18" is too much. I think I want to go SI/SO with either a 3" or 3 1/2" tip. I was thinking of going w/ the 18 and having it put as far back as possible but still staying underneath the heat shield. Any input would help.