I have to say something - cutting any metal out of the cab pillar is a recipe for disaster. If you took a decent hit side on the pillar would tear apart - right next to your head. Here in Australia performing that modification would be deemed an instant structural defect and the vehicle would be junked. Unfortunately the single cab of these trucks were never built with any reasonable car audio install in mind. I would install either 5.25" or 6.5" splits in the doors and windscreen pillars and fit a slimline sub box either under or behind one seat, and a 4 channel amp similarly on the other side. It would be more than enough to loosen your dental work and would sound way better than a 6.5" dual cone right next to your head.