while i agree that the beehive is a good spring all i am saying is the origional springs lasted 15 years so they must be good also.if he goes to the beehive spring he will need to go with different retainers but if he wants to spend the extra money it will work.

to the op,i think you need to send the injectors out for cleaning&flow testing,i will bet the cylinder with blown gasket has a bad injector.

It was 15 years ago but it seems like thats about the time the 377 was cheapened. Perhaps the base 6.2 was always a budget stroker. I have a feeling some early salvage 6.2 scorpions are coming my way,didnt know if anybody could say for sure which ones had the aftermarket heads crank ect .
Can break out the big black book and look it up myself ,if i can find the time

there was 3 different version of the 6.2 from Merc. 2 of them had MEFI 3 and one of those from Merc racing and the OP has Production side 320 hp PCM 555 version nothing special at all. Forged crank only if that, but I would have to double check to make sure for his exact app. Cooling issue and or lean condition (fuel and or cooling) most likely caused the blown gasket.

Water circ pump issue do not rule out - 15 year old pump - a common missed item. Just saying.

Today fuel injectors are the other big problem. Amazing what I see internally of fuel injectors, form corrosion to White / yellow tint aluminum Oxide to metal flakes, brite metal flakes, Aluminum flake, and the BIG ONE black rubber fuel lines balls or particles also fuel deposits.

Special note. ### Boaters need to change their rubber fuel lines every 4 to 7 years regardless. Its what you can not see internally of the rubber fuel lines that is degrading in which gets trapped in the fuel system and or the finer particles of it end up in the injectors and their basket filters. Anyways a tip for all boaters in which this process is often missed as well.

Change the rubber fuel lines for the carb apps as well. Not to forget those apps either

Thanks for all the info guys. I'm planning for the felpro marine gaskets and cutting the heads the difference in those and stock thin gm gaskets that were on it. The back of the block seems to have sand or corrosion in the water jackets. I got it all loosened up with screwdrivers and wires from the top. This seems odd since the gasket blew between the middle two cylinders. When I get it all sealed back up I will pop out the freeze plugs and flush the rest out. I also will send the injectors to be checked and a new circulation pump. The motor has just under 600 hours on it. It is clean inside and no contaminated oil. I don't believe it should need any other work.

Middle two are typical on a SBC.