Well, I don't know much about the W3, but when I had my Chevy regular cab pickup I was able to squeeze two 10" W-Ø's behind my seat. They absolutely slammed. I had a Kenwood PS200 amp that was pretty good. I've never heard a complaint about JL's in a restricted space. Check out their stealth boxes, they may have one for the F350.

 

Heh, I like my 15W-1. It's rated at 150rms and I've run 300rms to it for 10 years now. It will run in just over 1 cubic foot of airspace, but I recently built a box that is somewhere around 6. It's not as tight as the smaller box, but Oh man is that thing loud!!