79 Sea Ray engine replacement

[mlshelby]

I am new to boating and just bought a srv200 with the 228 mercruiser {305 chevy} engine. The block has been froze and cracked but has been repaired with jb weld and still runs, but of course i dont trust it. I have been a enginetrans tech a chevy dealer for 18 years so i will fix it my self. My question is what would it take to replace the early model 305 with a later model 350 {post 87 w/1 piece rear main seal. I know it will physically bolt in but what style flywheel and drive coupler will i need? I have no boat experience so ive never even seen how the engines hook up. If i build a 350 from scratch what all do i need to make it a "marine" engine. The engine i want to install is from a 90 pick up. I know i need brass freeze plugs and a reverse rotation camshaft but is there anything else? I have a edelbrock intake manifold that takes a Q-jet and bolt onto the later model heads properly but its aluminum, can i use it? This boat will never see salt water while i own it since theres plety of lakes around Michigan. Any help?advice much appreciated. Just want to understand what im getting into.