Try Summit Racing or Jags. They can probably cross reference the number.

wrote in message
oups.com...
Hi there,

I need a definitive answer to this question: I need a new set of piston
rings for a mercruiser 2.5L 120 engine and would like to find an
alternative set of rings to the genuine parts. I am led to believe that
this engine is a derivitive of a Chev or GM unit. The block has GM
stamped on it and the engine serial number is: 2773308.

Can anyone stick their neck out, based on cast iron experience and tell
me what other piston rings would fit this engine?

cheers

Terry