What motor do I have?

[jimmmy]

Hi gang. I'm new to this site and also to boats. I have just purchased a 78 Silverline with a 400 Stringer, but I'm not sure of the engine size. The guy told me that it was a 3.0L but, I'm wondering if it might be a 2.5L. It says 120 on top of the rocker cover. The engine model number is 990243D.Does anyone know what size it is?

 

[chiefalen]

2.5 / 120 not a 3.0

 

[jimmmy]

Thanks for the info. I may need to know for ordering parts.

 

[chiefalen]

if in doubt pull the valve cover you will see what you have stamped on the head.

 

[hystat]

3.0L has a vibration dampener on the front of the crank with the pulley, 2.5L has only a pulley

 

[jimmmy]

I'll check that out. Thanks hystat.