the measurements were spot on, here are some (iPhone) photo's:
Its centered, poor camera angle ..doh
Mostlikely you cant see it but the 1/2 bolts that go from the outside of the main bracket to the caliper adapter head had to be ground down to the thickness of the 3/8's head. When the 1/2 bolts were in place, you coldnt slide the axle in far enough to insert the c-clip. Thus requiring the grind down the head of the 1/2 bolt. Only other way w/o grinding down the head would be to use 5/16" thick steel as the main bracket, probally plenty good and strong but 3/8 sure is beefy lookin.
Showing a point on the factory C5 caliper adapter. This point makes slight contact with the ebrake backing plate. The caliper adapter still need to be centered just a bit more which would make even more contact with the plate. I need to measure how much of a spacer I need to center it on my axle, maybe have another member (that has a spare axle laying out) try it out on their axle and see if the spacing is the same. I will probally use that same thickness if its not more than .050. Looking at a dial caliper, it should be less, and use it to space the e-brake plate out just a touch more so only a touch of this bracket will have to be ground down so it doesnt make contact.
Showing the sharpie marks that were made on the inside parking brake drum to see where the contact point is. Entire shoe making contact to the drum with about 1/8" to the end.
All thats left is to find the needed measurement so the caliper is correctly center over the rotor (currently its not), same spacers for the e-brake plate and figure out how to remove the end of the dorman parking brake cable so it can then be shortened. Another member on another board probally had OE cables and the ends "screwed off".... these are crimped. I dont imagine that bing a stupid big deal but once its off, it will be a sinch to shorten the drivers side cable.
The idea on the ebrake cables mod would be so when you run the passenger side cable over the pumpkin and onto the frame rail (as factory) the drivers side shortend cable matches up so you can use factory hardware. Thats the concept.
clint