You shouldn't be running that high. I would pull that thermostat out (especially if its an auto zone) and replace with a stant (OEM). Follow the procedure in tech info for getting all of the air out.

We checked it out this past weekend ...

Engine was cold. From my house to Advance the car read 220F. It'* maybe 1/2 mile. Next time Rubix is up we'll test the ohms between his pcm and cluster senders.

with all that gunk around the cap opening I suspect the cap is plugged also. Check if you overflow bottle level is rising and contracting from hot to cold. You could still have air in the system thats not being purged out.