go as big as u want!..4 inches above the vab will be just fine inside the cab with all the windows closed...when i wanna hear the roar that it makes i open up the rear sliding window in the summer and enjoy my mini locomotive

 

mr T like the stacks i want mine higher by 3-4 inches i pull a 5 place snowmobile trailer and have sled in box and don't want a black sled by the time i get upnorth lol.will need two have a heat sheld.

 

Run 4 inch diameter 36 inch long turnouts and turn them to the side like my son did if you want louder. That thing was insanely loud.

 

is that 8 inch setup made of stovepipe?

 

I love the look of the stacks that are on huge CAT equipment. They are Flat black, 6" I think and are mitre cut types but with no gradual turns, just an abrupt, seam welded taper to keep rain from coming in overhead. Now if only I could get my truck wiht those and painted in REAL CATERPILLAR yellow and black... CAT with a cummins... hmmm