These will work for s13 and s14. I recently did the rear altima rotor upgrade on my s14 and for those of you who don't know about it here's the link:
#/f/archive-faqs/291...-calipers.html
basically you are keeping the same brake setup but you are going from a 10" stock 240sx rotor to a 11.5" altima rotor for better heat dissipation and more brake torque by having the caliper farther away from the center of the wheel (like more leverage with a breaker bar as opposed to a ratchet). The swap takes an hour or two and you don't have to mess around with e-brake cables and get a larger BMC/Brake booster like the full z32 brake swap.
I have an extra set of z31 caliper brackets, you would just need to get yourself some 03 altima rotors, bend your brake shields back and you're good to go. These are clean and painted with high temp black paint.
what they look like on the car:
**asking
50 for both brackets**