318 Overheating...Help!!
Well……
You have a new radiator so it shouldn't be plugged that's good.
Your gauge is a good one so it is probably reasonably close.
I would probably drop down to a 180 thermostat (but I don't think that's the problem)
Don't think that fan will cut it in the Vegas heat. This is just a comment. You are getting warm all the time and a fan doesn't really matter when driving at speed (over 30-35 mph or so).
Warm all the time is usually flow or tuning.
If the flow is to fast or slow it can mess up the heat transfer. For example a non-AC water pump with an AC pulley or an AC water pump with a non-AC pulley will change flow speed (this was the issue with one member's car).
Timing and/or AFR could also be the problem.
You could also have crap in the block. Have you flushed the system?