Good to see all the results Dana. You said in a reply to "Magic Transom Pictures" that the Gibson is straight thru so no water back up, correct? That is what makes me nervous in a lot of these mufflers because the water flow is definetly disrupted and not straight thru as Merc designed. In the clamp-on version can they truly just be clamped on and not have to remove the internal flapper on the stock exhaust?? NSF Thanks :2purples: