Has anyone successfully installed stacks with a shell/cap on their truck? I need the shell for road trips where I sleep in the back of the truck, but stacks are just way cool so I was trying to think of a way to do both. If a 5" hole was drilled in the roof of the shell, how could it be sealed around the pipe in a way that would allow some movement from flex while still keeping the rain out? I also notice most people drill one hole in the bed and Y off from there... but that would take up a lot of my sleeping space. Is there enough room to Y under the bed and drill 2 holes for the stacks? As a side benefit, I could high-idle the truck while I'm sleeping back there and stay nice and toasty! 
