droped front end on a 81 f-100

[giuricich]

I AM IN THE PROCESS OF LOWERING AN 81 F-100 STEPSIDE. I'M USING DJM I-BEAMS, WHICH NEED TO HAVE 1" KING PINS. OF COURSE IN LIFE NOTHING COMES THAT EASY I HAVE 7/8 ONES. I FINALLY AQUIRED F-150 SPINDLES WITH 1" KINGS. MY QUSTION IS DO I HAVE TO CHANGE THE ROTORS TO A 5.5" BOLT PATTERN. OR WILL THE 4.5" ROTORS FROM THE F-100 STILL FIT. IF I NEED TO MAKE THE CHANGE DO I CHANGE REAR AXLES OR USE ADAPTERS. BIG DILEMMMA. G.