how many hours should you go with springs . Also what would be a good head as an up grade to boost power with a cam

First of all you need to determine what's going on with your engine before you think about upgrades or performance mods.300 hundred hours on springs is really not that much depending on how the motor was treated,maintence and the environment is has been used.If this boat only saw 6k rpm's in the life of the motor springs and pistion rings would be something to look at. Did you do a compression and leak down test? What does blowing out "mud" mean.Would like to help you out dude but ya might want to be more specific.

What color is this mud and has your oil level changed? If the mud looks like a nice fluffy chocolate milkshake then you are pumping oil out the exhaust somehow.. I had a leak develop in the oil cooler which promptly made 5 quarts of oil "disappear"

Hopefully this isn't your problem..

working on the problem tonight I was thinking hydro lock motor makes a half a turn and thats it starting at the headers tonight and working my way down any ideas thanks for any ideas