I bought a set of used Arias pistons off e-bay, good deal right. So they said the pistons were to make 9-1 CR but they said it that they would make any B series
9-1 which can't be correct. Can it?

 

Arias makes pistons to achieve just about any compression ratio you want. They're 9:1 pistons are popular for turbo applications. You may want to get some more details and figure out exactly in which block/head combo they will make 9:1 compression. And for reference, most B series pistons are 81mm and are interchangable.

 

CR will depend on witch head you use