When changing compressor or exhaust turbines will the turbo need to be balanced to compensate for any change in weight/size from the non standard wheels. Also I read about someone using CT12 (the small 1ggte turbos) exhaust turbines in the CT12A turbo's! so they can run more boost! Dose this sound right? They said that the CT12 exhaust turbines were steel??Is that right? Would you think that set up would increase performance? Anybody done it????