does anyone know?

i'm rebuilding an eng...the mahle jugs have this # 90ZN2. believed to be RS p & C's, does anyone know what it means?
thank you

90ZN2 are 2.7 RS jugs. You'll have to look at the bottom of the pistons to verify that they are also RS.

piston id seems to be...34p13
thank you

Hmmm... those pistons should be too small for the 90MM RS jugs. (probably reads 84P13)
Decent reference table can be found here:

http://www.early911sregistry.org/for...270-Piston-I.D.