Mercury 2.7/8'' STD. piston ring numbers?

[smako78]

O.K. I'm a little confused Merc. # 39-6475A12 is for 150hp. S.N. motors 375- and below Merc. # 39-45155A12 fits 150hp. S.N. motor # 375-and up? Then I find Merc. ring # 39-78816A12?
So are these Merc. #s 3-pack? 6-pack? 12-pack ? for a 2.875 piston? Is there a single ring # also? Why so many Merc.#s for 2-7/8'' pistons And how many more Merc.#s are there for the STD. cast iron ring?
Steve

[ChrisCarsonMarine]

The 39-78816a12 is a box of 12 cast torsional standard rings for a service motor,the45155is moly filled high perf ring used in the bp and xs motors,if memory servs correctly.,Chris

[smako78]

I might put a molly on top and two cast! What is the 39-6475A12 made of? And does it fit? Steve.

[ChrisCarsonMarine]

Don't remember that one...

[smako78]

Thanks Chris,, Does anyone know if a 39-6475A12 # fits the 2.875 Low dome? And has anyone ever mixed cast (788) with molly (45155) ? I can get a good deal on the 39-6475A12! Thanks everyone for all the help!
Steve