Round back alternator

Thanks for your answers and reading , I did take this alt. Back to get checked and it was bad a diode , so they were kind to me and pick out a new one a square back 55 amps , tried it and it works just like my old original square back ,steady and only pulling 14.3 , yes I grounded one bush, if I were to turn this into a two wire alt which it is ,which bush is negative and positive? And would this be a good plan as I do have the parts just have to wire in. sorry 1969383S