What year is my 28hp Mariner

[FishAddict005]

Hey everyone new to the site and really appreciate any help I can get. I recently purchased an immaculate 28hp electric start long shaft mariner for a great deal. I would like to know the year and I was hoping someone could identify it by the serial# it reads 664L57149

Thanks

 

[Fun Times]

http://www.autorepairmanuals.biz/page/608045

28 el

664-571176 - 664-572505

1978

 

[FishAddict005]

Thank you boat_tech for the response.