If it works like i think it should I will in-stall stainless pipe for a long term repair. What do you guys think of my theory?

Port Monster thanks for the link. I read it and now see a simple modification is needed to my extension. I will weld in a water break to "turn the water around" and that should help alot. Thanks again!

SUCCESS!!!!!!!!!!!!!!!!!!!!!!!! Ran the boat in the driveway for about 20 min most of the time at idle (850 rpm) and pulled the risers and NO sign of water/moisture. If anyone needs info on how I made this work just shoot me a message.

It will be interesting to see what happens when you get it on the water. I think you need to let the engine get a good run so the constant pushing and pulling of exhaust from the cam overlap goes through its entire cycle; not sure where it is worse in the RPM curve but my guess is that it is not at idle. And, now that you did the work do you think that you could have added a water break in the original riser to prevent reversion??

Well, from that I was told below 1200rpm is when it would be most noticeable. The proper distance between the water and exhaust is key when you have overlap. As far as making the water break in the riser by itself I don't think that would have done it, not with the amount of water I had. On my next set I am going to weld in a break inside the tube just to be safe.

Most definitely reversion at least to one of your issues. So far your lucky no damage but the camshaft duration is to much for the oem exhaust system. The guy at Crane who told you that is incorrect.

Yes I would agree that The boy didn't know what he was talking about. Going to look for a good set of manifolds and risers during the off season. The motor needs to breath and my stock replacements just wont cut it.

Ok, SSSSSSSSSSSSSSSSOOOOOOOOOOOOOOOOOOOOOO it didn't work so well. Ran the boat for a few and still had the issue. Time to spend some money.......... You guys can stop laughing now....

You get an A+ for actually thinking about stuff and trying. Failure is nothing but the opportunity to start again. What caused it - a higher RPM?? And what about it do you think did not work??

Is your cooling system stock, or are you running a crossover?
Looks like you are running the Merc 420/525SC cam. Merc used that cam with the short GIL risers and cast manifold with SS tailpipe.