What year is my motor???

[c5engr]

I have a stringer I/O 4 cyl GM which I intend to sell, but haven't a clue what size or year the motor is. The # on the block is 2770087. The OMC tag serial # is W548333 and the model # is 990236E1. Thanks...

 

[hystat]

1977 3.0l