im not really sure how strict the emmision laws are there, but my uncle has a 85 camaro that he had straight piped and still could pass the emissions in phoenix everytime he had to. his trick was pouring a bottle of the emission pass stuff in the car and follow the directions on the bottle, then play around with the carb and make it run damn near as lean as possible for the test. so i would say keep it how it is, and try something like that. good luck to ya though