After replacing two head gaskets, coupled with an ongoing problem of the car over heating in traffic, I found the solution by talking to a Ron Davis radiator tech, and a tech from Performance radiator, in Phoenix.
I've had a Ron Davis radiator in my car for 3+ years, a mechanic told me (not Ron Davis) after getting stuck in Phoenix traffic and the needle buried at 250 degrees my radiator was clogged. So I called Ron Davis and told them I drove from Palm Desert to Phoenix in 105 to 111 degree temps and the card did not overheat, however when I slowed or stopped in traffic the needle would peg at 250 degrees.
Both techs told me I had an airflow problem not a clogged radiator. I had a set of SPAL fans in my garage that I purchased 2 years ago, I had a mechanic install the fans, WOW what a difference the temperature gauge does not go over 200 degrees at any time, I cal leave the car idle for 30-45 minutes in 105 degree temps and it stays at 200. I'm getting better MPG, performance appears more responsive, wish I would have done this 20 years ago.

Hope this helps someone

 

the temp can be lowered. programming the Prom. one of the first mods on the ta do list

 

Correct, however the stock fans are inadequate to force enough cool air through the Radiator.