i recently acquired two new fb's. one of them is a parts car and the engine is supposedly good. (came with engine and trans.) now that im gonna have an extra engine to mess around with ive been thinking. Is it possible to use a 20b eccentric shaft if i just happen to decide to throw another rotor on the end of a 12a? ive heard of people doing it with 13b's but wasn't sure if it would work due to rotor width. just curious to know cuz the extra engine will be lying around.