Bought a 79 22ft charger last  year with a harman marine bbf . Ran great all last summer , put the boat away for the winter and took it out 2 weeks ago to silver wood . changed the oil when i got home and it was dark grey . Is this a sign of a blown head gasket .Pretty new to the jetboat scene  and wanted some advice before i went pulling the heads . Thanks

One of the jet guys will chime in about water pressure and releif valves and stuff any minute.

should i replace the intake gasket  first because its cheaper and easier access ? It didnt seem like a substantial amount of water in the oil just a real dark gray .

You have to take off the intake to get the heads off , so when you do check to see if there is a obvious leak in the gasket before you pull the heads.
Don't always assume the worst!

always assume the worst!     then be thankful when it not 

What type of exhaust do you have?? Milkshaked my oil real bad last fall... My first thought was head gasket...  Ended up being the spring in my Basset t-valve was bad... First thing you should do is run a compression test... Depending on how old the motor is it's not uncommon to see a variation of 10 to 15 pounds between all 8 cylinders. Now if you have one or two that are way low then the possibility of a head gasket is real... Good luck.. Andrew

i have harman marine water logs, i did notice that one of my exhaust flaps was gone i wonder if water could have flushed in the motor when slowing down . Well i will take it out one more time with clean oil when the weather permits , 60 mph gust today at my house . Thanks