Thanks guys!
Anything more than two 5" next to eachother looked like to much.
Under the bed is a 90deg turned upwards then it goes into a large Y pipe. From there into the two seperate stacks.
The cool thing is in the cab on the floor we installed a button. When you push it it opens the exhaust right by the down pipe fitting and fires the exhaust onto the ground. We did this to try and help the EGT's when pulling heavy loads.
The pipes (stacks) have actually been shortend 2" because i thought they stuck up to high. It looks even better now. I was gonna take pics today but the truck is all dirty from the rain.