mercury 7.5 , 7391A3 / 7391T3 pistons

[JJB]

I have a 1979 7.5 mercury OB . the pistons in the motor have 2 rings on them. I notice the mercury replaced them with a 3 ring piston type. There are still some old stock 2 ring pistons around or should I replace them with 3 ring type.
7391A3 vrs 7391T3 pistons . thanks for the input Jb

 

[jimmbo]

Either will work

 

[racerone]

Actually the older motors had 3 rings on the piston and newer ones had 2 rings.