a b20 is a bored out ls block. they use the same rods and crank but a bigger bore. i would sugest doing a crvtec if you wanted to put in a b20. you will need vtec head bolts, oil feed line, crv head gasket and a new crv timing belt if you are using a crv water pump. the oil pump will be fine, it is the same part # and pump as a GSR. the motor mounts will be the same as what you got right now and the tranny will bolt up. and the wiring harness is a direct swap.