The header pipe for # 7 and 8 cylinder is shorter than the rest. A small amount of reversion at idle happens regerdless of silent choice or not. A small amount of moisture makes it up to the port but not into the cylinder. It soakes into the composite header gasket and causes corrosion on the exhaust flange of the aluminum head. It can be repaired by machining it and welding and remachining. the moisture also causes heavier carbon deposites on the valve stem and eventually the valve will stick in the guide. Removing the ring on the valve seal on the exhaust valves allows a little more oil down the guide and helps prevent sticking. To lessen problems later, do not use the Merc composite header gasket. Cometic makes a Stainless multi layer steel header gasket. I can try to get you the part number later. They are expensive but reuseable. Also just try to minimise the idle time. I have both steering pumps running my steering (special plumbing required) so I can use one engine in long no wake zones. Allows you to push that engine up to 1200ish stopping the reversion.

Congrats on the deal of the century!!!

So if I just bump the idle up when I'm gonna be idling for longer periods of time would that help me out?

I really appreciate you taking the time to explain that.

Make it dry to the tips and forget about it

Yes just try to minimise the idle time. Dry to the tip is too loud.

Never too loud...

Never too loud......if you get pulled over just tell them your mufflers are in the shop getting worked on.

Seans dominator with 500efi's and dry exhaust was ridiculously loud. People at muscamoot were not impressed when he let it sit there and idle facing the oppositte row of boats while his battery charged.

I have to put new tails on mine, was thinking of going complete dry....avoid it now??

I've had two boats with dry tails and whatever I get next will have dry tails. Nothing is better than pulling the headers and seeing perfect looking valves, not some corroded crap because I cared what some yuppies thought. And I also run 100oct low lead from the airport so the smell is outstanding if you like that kind of stuff

Depends on where you boat. The west side of MI is strict. Higgins is ok, my buddy and I got pulled over with twin 572's with dry and were just told to stay in the middle of the lake. Noone I know including myself has had any issue on St. Clair. A few of my friends have dry and it sounds great! If you like the sound go for it.

And Kid, when your in the line dry doesn't matter, people frown on it no matter what ya got.