radcap or thermosat

[brad mcintyre]

I am also going to change stat its a couple years old. if its under 90 its not a problem 

[myk]

The 60 year old engines where not designed to run at those temps. Will it blow up at 200 or 210, no, but its hot for the engine, it will ping, it wont make optimal horsepower. The rad needs to be filled no higher than an inch below the top on a stock system.
   Now, on to questions-
1: does it run that hot at idle and cruising down the road or just one or the other?
2: if its only at idle, does it have a shroud, how far from the rad is the fan blades, what fan is on it.   specificly.
3: on top of whatever else is answered or discovered, i would reccomend a 160 stat

I'll answer.
1. Cruising down the road it's 140*.  After about an hour and a half of stop and go it slowly creeps up to 210*. 
2. Stock shroud, fan is about 1/3 into the shroud.  Fan is a 17" Summit thing with 6 blades and spun by a Hayden 2765 clutch.
3.  Really?  I just swapped out my 160* for a 180* because I became convinced that my cruising Temps and warm up time are too cold and take too long.  I'm so confused...

I was aiming that at the op, but now your response has me pondering more questions.... cruising at 140 and idling at 210 tells me you have an airflow problem at idle and plenty of capacity at cruise. In comparison, my car will warm up in a few minutes of idling to 180, idle all day at 185 to 190 on a 100 degree summer day, and cruise at 180.

Not to steal the OP's thunder but what do you recommend?