JE makes 84mm big bore B18C1 pistons. Anywayz, I'm not sure if you can use B20 pistons. For starters they might not yield the advertised cr in a GSR motor. Also B-Series VTEC motors have bigger valves then Non- VTEC motors, so that might cause a problem as well. I don't see the point of getting JE B20 pistons when JE makes big bore VTEC pistons.