I agree.

We ran these old mid - late 60s Mopar motors on a dirt track. 220 is nothing to be concerned about, but it is time to look for a possible problem. After a hard race on a hot evening, our motor often was at 220 by the time it got to the pit stall. Like most others, we were spraying the radiator down as soon as we could get to it as it entered the pits, as soon as the temp started to drop (which was very quickly) we went on to our spot and shut it off. 230 is the shutdown range if the temp isn't dropping really soon (even warm water across the radiator core drops the motor temps fast), 230 could cause the rings to start to loose their tension and could cause a loss of power, long term, and if done multiple times. 235 is shut it down now time. Then let the thing peculate until its below 180 and you still are probably OK, if it becomes a regular feature, I pulled the motor down for inspection.