I'm thinking of putting bigger brakes on the front of my frst iv currently got st150's on their but iv got rid of the rear drums in favour of st170 rear hub setup an iv been told that having near enough the same size discs on the back isn't a good thing? Iv also been told that I can use mk3 mondeo front calipers with st170 discs or calipers an discs from the st170. I no with both I have to drill the hubs from 10 to 12mm but I don't no if I have to add washers or spacers to make them fit correctly? I would prefer to have them fitted without washers ect any help or advise on this

Thanks in advance
Chris