24 inch shroud..6 blade steel fan. Internal trans cooler in alum rad.

at 200 I'm not comfortable. I discussed this earlier with others who claim 220-230 is fine for their old motors. I ran a new analog gauge with the stock gauge on My BB and 180 was center of the dashboard gauge. 200 was just out of the comfort zone..210 pegged it. My experience and driving old iron for 56 years is old motors don't like high heat. They last and run longer/better at 180 to190. Oil doesn"t last well running high temps

I have spent many years chasing cooling issues in customers vehicles and have resolved EVERY ONE OF THEM. It can be a time consuming process. I also spent over 20 years in various engineering positions some of which involved temperature control.
I have posted questions twice and only received a partial answer to one. In reading the above as well as you other posts two things JUMPED out at me.
1. 200 degrees is nothing to be concerned about. 210 also OK if it stays there.
2. You are relying on an auto meter gauge which I have seen be out of whack by as much as 40 degrees as well as other brands. They always go seem to go further out of calibration the warmer they get. While yours is probably OK the only way to be sure is with a thermocouple and digital meter.

Is this a mechanical or electrical gauge? If electric available V (typically lower at idle) and grounds can come into play and impact the readings, especially the sending unit ground.
You haven't stated what the ambient temperatures are or the conditions when this occurs. IE:
1. heavy stop and go,
2. just off the hiway,
3. and how long it takes under various conditions to reach 200 or 210.

While I'll agree your problem (which may not actually be) seems to be related to a lack of air flow it can also be a number of other variables stacking up. IE:
1. The fan pitch is not enough to pull the air for your 3 row radiator.
2. All radiator cores are not created equal. The size of the tubes, their wall thickness, staggered or in line, the number of fins per inch, the thickness of the fins. whether the are louvered or not and how they are attached to the tubes.
3. A clutch fan as suggested by another may tip things towards the cooler side as they are designed to move a lot of air when needed. (think a cop car idling for hours in Az back in the day or a forklift running around in 100+ degrees heat ) Do get a thermally activated clutch if you go that way.
4. Coolant? Anti freeze/water ratio

Answering/verifying questions previously asked should be step #1

Implement simple things like making sure the shroud is sealed to the core #2

Verifying your readings via thermocouple should be step #3 The beauty of the T/C is it responds instantly and is accurate to a .1 or so of a degree. You may not choose to do so or need to as you situation is on the ragged edge but definitely removes any doubt or questions.

Gathering and Recording the Data (answers) to all above posting and questions Step #4

Analyze the above answers to resolve the issue.

I will bet putting the car in neutral and raising the RPM to 1500-2k will make that temp start dropping

reving in neutral didn't have an effect. 50/50 mixture on coolent. 210 is in the overheat range and I would never run an old motor(meaning pre 80's, not condition) at 210. Dash gauge would be pegged.

Increasing the RPM obviously should pull more air through the radiator. If is not having any impact there may be a clue there
not trying to be offensive in anyway but rather making an observation.

I ran a lot of pre 80 Mopar motors on dirt tracks. Without a doubt, I can tell you 210 is not a problem, unless the cooling system is not pressurized. Water in an open pot doesn't even boil at 210. With the cooling system under pressure, 225-235 is hot, and those old Mopar motors did OK unless it stayed at that 225-235 for 10 minutes or longer, under pressure.

Next up, factory gauges were a best guess as far as actual temperature is concerned, the "readings" were generally all over the board, I doubt many were even close. Just because you had one that was in the hot range at 210, I've had several that probably were just into in the operating zone at 200. If you are basing your overheating on a factory gauge with an assumed overheating temp of 210 because of one factory gauge, you probably don't even have a problem you think you have.

3rd, if reving your motor did not effect the temp, you either didn't reve it steadily, or properly. You should have brought the rpm up about 500 rpm, and held it there a minute or so to see if the temp started dropping. If it would have failed to drop then, your perusing air or water flow probably isn't your issue anyway, because that extra 500 rpm would do the same thing as more air or water flow.

as a side note..as far as I'm concerned any and all who submit that a temperature of 210 is fine to run an old engine : don't bother. Not to be nasty but I'll never accept that and submitting and reading is a waste of time for author and reader.

Just another side note..IF 210 was fine..then why only a max of 195 thermostat. is available. New engines have different cooling and pressures to run at.

do a search on cooling and tuning issues...
210 is not hot so quit arguing with us
This thread is another broken record

It is apparent that not only are you ignorant of what a thermostat's purpose is, you are also ignorant of the normal operating parameters of a cooling system.

You don't have a problem, other than the one involving your understanding of how a cooling system functions.

So don't waste our time with your misconceptions.

And love it when one asks for help and then later announces he's an authority on the subject

And to OP, I am truly sorry for wasting my time trying to help, please accept my apologies. If you really want to cool things down, try some LN2 in place of that old 50/50 mix.

If revving in neutral didn't help, your fan is probably junk. Not enough pitch or not enough blade width. Try a different mechanical fan with more / bigger blades and see what happens. They are cheap enough in the junkyard. I had that happen where the car would boil over when idling or trying to go through the drive-up window line at a restaurant. Pegged the needle at 260°. It ended up my fan just wasn't moving enough air. I put a bigger fan on it (with a fan clutch) and it completely solved the problem.

lol....You do understand that 195 is the temp at which the stat STARTS to open....right???

yes...I have a firm grasp on the obvious unlike some others...I'll request the moderators close/delete this as it has gone off the target question. Thanks to some for info...thanks for no real value information to others

most t-stats take approximately another 10-15 degrees to fully open.
i used to be concerned about running hotter than say, 180, but not any more. 230 or 240 for extended periods might make me just a little concerned, but if the temperature returns to around 220, no big deal.
a 16lb. cap with an overflow return tank, plus a reasonably sized and clean radiator, [even a 22" will cool more than you think] and the fan[s] of your choice, will cool all but the most finicky rides.
plus, it helps keep the engine internals cleaner, longer.
my opinion and experience only, after playing with these toys for over 55 years.
obviously, your mileage will vary.

WHAT ABOUT A FAN CLUTCH???? It was mentioned more than once and we still don't know if it is direct or with a clutch. Also it is a aftermarket fan? Flex blade, solid what? Not to be rude but if you want suggestions we need to know all the particulars.

I do not believe a clutch fan is going to do anything else a direct fan is doing at low speed or idle. I have a newer miloden thermostat and it opens at about 190 per my gauge and at highway the temp on the gauge reads around 180. 180 stat

A faulty fan clutch can slip too much. If you don't have one, it's a non issue at idle. If you do have one, it's a possibile problem.

Just for perspective, there were many times we ran 454 Chivvvys at 260* ALL DAY LONG in the AZ/NM/TX heat while towing a trailer & load that weighed 25,000 pounds. And the 454 would be back to take more day after day. Just say-IN!

The OP wants to make his car run 180 or less at idle. It's certainly possible to do that with the right combination of parts and tune. Why is everybody trying to convince him to let his engine run hotter? So what if you can. He doesn't want to.

TY