try the iboats.com site it has information on almost all the boats

there should be a capacity plate near the rear of the boat if not on the transome itself that will tell you what the maximum load and horsepower are.

Sea King boats and outboards were sold by Montgomery Ward many years ago. I am not sure what company manufactured  them for MW. 1975 models won't be found in the NADA books and I am not sure where you will find a value. What size boat is it? What hp was the motor that came with it? You might check the USCG website as they do have links to different sites such as boating recalls. Maybe they will have some type of reference for you.

You can also get information on all motors,boats, trouble shooting anything. This site is owned by a Marine repair and tech's.( www.themarinedoctor.com ). You will need to sign up but it's free information, once you get into this you see what they do.
Dennis

the boats 14 foot it didnt come with a motor. but i got a 55 h. for it. still havent found the boat on the net . about to try looking at this uscg site thanks. oh yahh it holds 6 peaple.

I had a 14' Seaking with a 35HP OEM motor. It was made by Evinrude, and used the parts from that manufacturer.