As I had previously done the dual pot drum/drum master conversion on Ol John Lee, just prior to the accident, I simply transferred the master to the 1965 truck and split front from rear as detailed in the link above.
Here is what we finished with. Plenty good but somewhat a leg builder....fully manual.
Upon cracking 4 pistons on 87 octane gasoline and a suspect rebuild of that fine 68 olds 250 I had a new Oreillies 75-79 non integral intake long block installed and the Chevy Astro Van T5 trans. Acceleration was up, top speed was way up and it was a job to dog John Lee down from speed relying only on the manual master cylinder.
Comfortable with drum brakes, had em all my life and they work great if ya understand how to maintain them....I had John Lee into the shop this week for a new rear main seal.
Seems its not uncommon for crate engines to come with the inexpensive rubber rear seal, which not only drys out in storage but seems a rampant number of them come installed backwards, pumping oil out instead of pushing it back in. So...while it was in I elected to do a final brake upgrade....addition of power assist.