What does it take to convert a chevy 350 to a marine engine?

I'm looking for a project boat for over the winter. Most of my boating experience has been on 24-28ft cabin cruisers running mercruisers, so I'm looking for a similar hull I can fix up. Is the whole block different, or can you convert a standard chevy?|||It's mostly the cam, lifters and looser springs. Marine engines rev higher and longer with less torque braking on the shaft. There are marine kits in JEGS and the likes.|||Alot of time, money and headache.|||the difference between a regular block and a marine block is the marine block is coated inside to prevent rusting,when the engine is in a car you use antifreeze which wont rust,but lake water is used in a boat and will rust|||The block is the same, but the heads and manifolds are different. If you plan on using a car or truck motor, you will have to replace those, plus the alternator has to have a flash protector, as does the air cleaner. The carb has to be a marine type that is Coast Guard approved also. You'll need to do some research so you won't get cited for driving an unsafe boat. (You don't want it exploding in the middle of the lake or ocean.)|||Ok, to convert a standard 350 to a marine take a bit...the block it self is almost standard except the freeze plugs are brass instead of aluminum, than you probably already know this but than you have to convert your alternator , because it has to be complete spark proof and same with the distributor, depends if you want more power than you change up you cam, pistons , rods , bearings and such...but most import is that your electronics are sealed..and your carb vent return line goes back into the carb instead of venting straight out...if you need more help just e-mail me..|||Your best bet is to get a reman engine from Mercury if you do not have all the marine electrical and fuel system parts off the other motor. They sell a complete dressed motor. Drop it in and go. If you have all the electrical and fuel system the swap is easy. As mentioned, install brass expansion plugs, replace the cam shaft, the M/C is ground to run at 4600 rpms, replace the head gaskets if it is an older 5.7l you are using. Good luck in your project.