71 Demon 5x4.5" front disc swap questions

Well got my Demon moved and wanna start pricing/locating parts for a front disc brake swap..

I have done a little searching and found disc swap brackets from Scarebird that run the 9" drum spindle/hub(studs) Toyota Previa 10.75" rotor and Chevy caliper

The Toyota rotors have a predrilled 5x4.5"BC and you're supposed to have the rotors redrilled for SBP BUT I am wondering if the hub(5x4"BC) could be redrilled for 5x4.5"BC?