Flat tappet to solid roller...

There is one more thing I need to ask about and it's running temperature.
Before cam swap I had serious heat issue. My engine would eventually overheat when left parked and idling. I could not drive much in traffic etc.

After cam swap I left the car idling and in never exceeded 170 degrees, I did not change anything in the cooling system.

Any guesses what could have been wrong before? What could have cause excess heat?

Also I did not touch the carb yet and set timing to 18 initial as it was before the swap.

Also before the swap I could not keep the car running when in garage cause it smelled very rich, now it seems to be much better, I could let to run in the garage with open doors...