Desperate need of help....Blackbird's rear disc conversion kit

[FLYNAVY30]

So a few years ago, I bought a rear disc conversion kit from Blackbird's Custom Trucks (forum vendor/sponsor) for my '72 C20 Suburban (8 lug/ Dana 60 rear). Ive been running the set up for four years now, and unfortunately need to replace one of the rotors, but have no idea what rotors came in the kit, as that was apparently a closely guarded secret so that people would not duplicate their kit. I've tried numerous '89 and later Chevy 8 lug front discs with no success. Blackbirds unfortunately went out of business two years ago, and the forum member who handled their interactions on the forum hasn't been active since 2015. If anyone can offer some assistance, it would be greatly appreciated as this issue has had my truck sidelined for over a month.

Thanks,
Greg