The disc is a plain style (no bearings) with a 6 bolt 4.5" pattern. It is bolted to the spacer with 6 socket head cap screws ( 1/2"-NF x 1"). The spacer is fastened to the hub with the press-in wheel bolts. I rotated the angle of the caliper to clear the steering arm. This style of modification keeps all of the original bearings, seals and wheel spacing and could be converted back to original drums with no retro-fitting. I have also made new mounting blocks for the back of the front springs and a new stainless steel battery tray as per the originals. It is great to be able to use all of my employer's facilities at no charge and I live just one block from work.
Gerritson