Look at my specs for the motor. Your also not bossting 15psi on a stock sleeved b20, nor making 200+whp.
With the poor R/S ratio that the B20 block has, your asking for trouble reving past 8Krpm. Were you even making power that high in the rev's? Or was it just pointless running of the motor? What kinda numbers did it put down? Where did it lose power?