yes pre 1990 front shee brakes will not work unless you wanna weld up your own brackets to the blaster spindles, they are the calipers that ride on the pins, not bolt on, the bracket with the pins is what bolts on, and the extra width of that bracket is what presents a problem,
1990 and up are the calipersa that will bolt to norman420 or 03+ blaster spindles, and the screws that hold the disc on are recessed on the +1990's, the ones on the older spindles stick out and will hit the caliper as they spin