I worked on inboard motors like that 383 for 10 years at a wood boat shop here in town. Only thing is that if it was used in salt water and didnt get flushed out it could be very rusty in the cooling jackets. Of course if it was a closed cooling system or used in fresh water then your fine.

I still have a 69 440 from a house boat with all its boat stuff still attached, someday I'll find something to put it in

Coolest motor I got out of a boat was a 409 dual 4 barrel motor that turned out to be from a 62 Impala! IT was 100% complete and running for $1000.00 I sold off the boat crap and had it ready to put in my 65 biscayne wagon when someone found out I had it and made me an offer I couldnt refuse!!!!!!!!!