Found a bad wheel cylinder on the LR yesterday (seized and leaking bleeder screw), hope to pick up a replacement today. There may be other brake issues too, but I need to fix this first one before further tests.
Also, I've determined the bed wood that came with the truck is not correct, both the mounting holes and the plank widths are wrong. So new wood will be needed as well. Details here -
https://67-72chevytrucks.com/vboard/...d.php?t=838551