You did not say your ground point but I would say almost everything would have continuity to ground.
You need to unplug everything on a circuit number and check ohms to ground as you plug each plug in. Any solenoid has a coil and will have low resistance to ground.
Say if everything on the 361 circuit is unplugged and you still have a low resistance to ground then you have a short in the wiring harness.

You are still chasing the 361 circuit are you not?

 

Final Update:

It appears the problem wasn't in the 361 ckt. As I was testing yesterday I focused on the starter solenoid since I was getting a dead short to gnd across the power
terminals on my last visit. When I disconnected the wires from the solenoid I
lost the gnd condition. I purchased/installed a new starter solenoid and no
fuses blew and she started right up.

Bill, thank you for your help and I am glad the truck is running again.