Looking at buying a turbo back system as my next purchase. Problem is, I'm not finding some of the info I'm looking for. For one I want to do dual stacks. So I'm looking for a kit that is 4" dp to 5" straight pipes all the way to the bed into 6" stacks. This trucks my play toy so I do want the sound. All the kits I find that say 5", don't tell me if it's a 3.5 or 4 dp, or say if it's 5 inch all the way back, or 4 inch to the bed than 5". Am I not looking in the right place for info? I'm so confused after looking at so many different kits.