[Walt Fricke]

I'm not a 930 guy, but this must mean that the 930 piston top doesn't have valve pockets or funny asymetrical shaped domes like the CIS pistons have. Otherwise you couldn't use a mark which was the same on all pistons to orient both banks toward (or away) from the flywheel.

930 pistons have a symetrical concave top, rather than any kind of dome? To keep the CR down?

This must also mean that the 930 pistons have offset wrist pins, and Porsche wanted them all to be in the same relationship to crank rotation. Probably for anti-slap.