Advice on replacing 4in straight pipe with stack
Im replacing my 4in straight pipe on my LBZ Duramax with a smoke stack. Iím leaving the 4 in from down pipe to my new 5in stack. My real question is, how big should I make the hole in the bed for the stack? The stack is 5in Inlet to 8in outlet. So Iím wondering if, instead of making a 5 in hole in the bed, should I make one slightly bigger than 5in? And do Iím wondering if I need to fabricate some sort of 5in rubber seal to go between the stack and the hole in the bed, to eliminate vibration from the stack. Iím assuming the stack would rattle and vibrate the metal bed. Help!
2006 LBZ, straight pipe, Egr Delete, wicked wheel 2 billet turbo wheel in stock turbo, s&b cold air intake, transgo jr shift kit, edge juice with attitude programmer, newly installed Mahle headgaskets and ARP head studs.
Last edited by OkDually; 03-30-2019 at 09:58 PM.