I'm happy with the coil strengths on my Seawitch. The lower flipper coils are AQ-25-500/34-4500 and I obtained them from Pinball Resource. The uppers are J-25-600/34-4500; they are red Stern coils & may be the originals. If you go too strong on the top coils you may end up replacing broken drop targets on the center bank from shots off the upper left flipper. I've replaced one so far.