OK Guys I need Help!
T bucket , early Ford spindles. Disc brake issues.

All the companys list disc brake kits that utilize "midsize GM 69-77" rotors and calipers. What is midsize? I really want to run 6 lug on 5.5" circle. Can anyone help by giving me a heads up on a "midsize " rotor/hub that would be 6 on 5.5?
I know that Chevy , Isuzu , and Jeep used this pattern. I got from NAPA a rotor/hub for a 3/4 ton Van. But I cannot get bearings to fit! I supplied Timken with the bearing dimensions and they said "no such part".
Does anyone know the dia of the wheel stud flange on a 5 lug rotor/hub? If there is enough room to weld up and redrill for 6 on 5.5.

Thanks to all who can help me!!!!