My first parade

[P.S.]

My 31 Tudor has crept along at parade pace in 90 degree heat, never got over 160 degrees. Has a 6-blade plastic fan and a new radiator. The trick is to get your idle speed down super low, then just use the spark advance for "speed control". I never sat with my food on the clutch. If we were stopping, I would slip it out of gear into neutral and keep my foot off the clutch.

The car could have done that all day long and never overheated. Your horn failing should be your biggest worry.