Oh yea, Mitre cut stacks on that bad boy would look sweet. Just don't have them sticking up above the cab 
6" miters just about the same height as the cab would be perfect.YES. IMO, miter cuts would look sweet on your truck! It has that look that would really be set off by stacks. IMO, make them stick up just barely past the cab (flush with top of cab or maybe 1" above). Plus with that short cab of yours, it'll help opticaly lengthen the cab some, and make the truck "appear" longer. Go for it!!