i installed rear disc on my 73 ....my calipers i bought of some guy who machines them they have the engraving ke engineering ...my set up uses a 86 maxima caliper and 300 zx non turbo rear rotors ......yes 300zx i made the mistake and thought they needed the 280zx ones when i installed them the pads only got about 3/8ths of the disc ....i haven't tried them out yet since i am very busy to even bleed them so im having my mechanic finish it off .....looks aggressive with the way bigger 300 rotor ....best part is my my parking brake actualy worked before i sent it to the shop ive had my z for 7 years and it never worked ....the conversion ran me about 300 bracket set $100 calipers (salvage yard) $23 rotors $23 each pads $25 bucks all new brake hardware $25