210 is what todays cars run at normally --thats not hot IMHO--now 240 you do not want to see on your gauge for very long--180 stat is perfect--along with a 13 or 15 pound rad cap!!

 

The thermo cap is in the return tank, coolant has been cooled by the core.
Use a pot of water on the stove and a known thermometer to check cap.
210°F isn't bad, just need a higher pressure rad cap to prevent boilover at shutdown.

 

I agree totally! 210 is what every modern car's temp is at and it goes up to about 230 or so before the electric fan/s come on. The reasoning is that the higher temp an engine can run at, the more effecient it is. Known fact! I keep a 210 in mine all the time w/o any problems and it's bored .060 over.
The most common mistake is someone putting a non vented cap on an early car that uses an open system and vice-versa. All '67-'69's are vented/open systems. The next biggest issue is no fan shroud being used. The original design works very well.
What I did on mine was changed the solid fan that came on it to a clutch fan. More horse power at a cheap cost. A/c equipped cars had them from the factory and it was an option you could have purchased. And don't forget to pressure test the cap to be sure it's venting when it's supposed to and not early. The spring tends to wear out and cause it to vent at a lower pressure then it should.
Original gauges work fine but a mechanical one is best. You know for a fact what it is at all times and don't have to worry about a faulty sending unit or high resistance in the wiring to give a false reading.
Hope that helps you some.

 

Update: The electric fan is a pusher. (Also, fan is hardwired into the keyswitch - it's always on). There is only +/- 2" on either side of the fan from the edges of the radiator. No shroud.
I have recently flushed the entire system, hoping that any buildup or blockage might be broken loose. Refilled system with Water Wetter, Antifreeze, and water. Running down the road, it never gets over 190 - 195 degrees. Sitting at a stoplight, or stopsign - it continues to climb. Luckily, I been able to get moving before it gets ridiculous, but it has gotten up to 230 +. Just real scared, I'm gonna do some serious damage.
More than willing to swap out for a new water pump, or bigger fan.
I do appreciate all the good data.
Thanks again.

 

Being a pusher fan, that would put it on the grille side of the radiator. Where space allows (you'll have it), a puller fan on the engine side is preferred. The fan not only pulls air through the radiator fins, but it also blows air across the engine to help cool it. With a pusher fan, air movement across the engine gets cut down by the radiator.

 

That's what I love about this site - is the knowledge that's out here.
Ok, I stand corrected. My fan is a "Puller". It is on the engine side. It does pull and "push" air when it's running. But obviously, it may not be blowing enough to cool the engine. I do have a cowl induction hood, which I would have thought would have helped warmer air escape a lot easier than a stock flat hood. I'm still thinking about swapping out for a new water pump, and maybe getting my radiator "rodded" to make sure there's no blockage.

 

Not particularly, the junction of the windshield and cowl panel is a high pressure area/volume. So with the opening, air is going from the outside to under the hood, a low pressure area - Physics.

Same with the engine compartment/radiator, in front of radiator, high pressure; engine compartment, low pressure.

 

No shroud limits the air being pulled past the radiator to just where the fan/s are. The shroud helps to funnel air across the whole area of the core which will make it run cooler. An electric fan that has a lot of age on it will also have a lower volume (runs slower) due to the brushes being worn in it. That's a long shot, but it does happen. If your fan looks reasonably new I would doubt that being the problem. Look into a shroud for it. I have a feeling that will fix the problem. If you have access to a laser thermometer you can point it at different spots on your radiator and get a better idea of it being clogged or not. Could be a combination of the two giving you higher than normal temps. I've seen radiators that are actually cool to the touch in spots with clogged passages. Not that I would recommend touching a hot rad, but I don't have any sense anyway

 

A fan shroud might help, but it would only be while in slow traffic or idling. Out on the open road, a shroud will act as a shield (restrictor) since the fan has no effect over free flowing air, and the funnel down effect of a shroud is only in the way at that point. I've actually seen guys where the fan shroud was the cause of restricted air flow through the radiator, resulting in overheating.

 

True, but he did say it was overheating at idle.