I checked both, and tried them too.
Neither fit, this is a Tyga top end rebuild kit. They forgot to ship the one top end kit with the order, so when that arrives this week I will check and compare.

What is odd is that the piston, according to the web site parts list should be a 13104-KV3-830 - D piston. A is 13101, B is 13102 so I assume this is a C?