Finally bit the bullet last Friday and drove the '68RR to work in Houston in the 95+deg temps. The car ran fine on the ride in at 0645 (no traffic) and on the ride home at lunch (moderate traffic / stop-n-go) with the temperature gauge sitting right around 180deg the entire time.

However when I pulled into the garage and let the car sit for 10-15 minutes it started to blow coolant out of the overflow tube. 5 minutes later most of the coolant was in a puddle under the car.

My question is this.......it didn't appear to me that the car was overheating based on the temperature gauge (brand new electric AutoMeter) so what could the issue be?

Do I need to add some sort of coolant recovery system or catch can? If so can someone recommend a kit?

I'm running a stock 440/6 in the car.