The low rpm/low speed drivability problems you described on the other thread indicates the idle circuit is at fault, nothing to do with the main circuit at all. However, I would recommend you go back to the baseline setup (150 main jets and 175 air correctors)and start again. Lowering the fuel pressure was just step one. You should definitely heavy up the idle jets next, go ahead and start with the 55s and see what happens.
Mike
