340 overheating problem

The pump is fine. We went over all that last week when then engine was torn down. To make a long story short. This is a fresh rebuild of a rebuild motor that had only 100 miles on it. ( we heard a noise. Engine builder took everything apart, couldn't find a problem. Checked everything Thanks for helping out. Text me when ur out of including water pump. Added better cam suited for this setup. Changed flexplate same time. Noise gone now) hmm. anyways. Even with my last setup she got up to 210-220. Today was a hot day tho.30 degrees Celsius. But you guys down south get even hotter. So there's no excuse.
I've tried to bleed air out of the system as well.
I've always been concerned with this gauge cause its my only gauge that isn't autometer. :s.
thermostat is definitely working.
My rad cap is 16psi. It is not over flowing when it's hot.