I vote for the 3 core rad and a thermo clutch fan. Mine never overheats and that's without a shroud. What part of fl are you from?

From what I've heard the SBF operates best when it's up to temperature. You my get arguments on this but most seem to think around 180 is good. Putting a 160 in will only bandaid the problem. It will start to cool sooner. If the fan and rad are not doing their job, if you sit long enough, wit will still over heat. IMHO

GOOD ADVICE MS

IMHO, a 192 degree thermo should be used. Engines perform better at around 190 degrees, and give longer life, if cooling system is working normally. This is my experiences on these "Infernal Combustion Engines"
Howard
 

Last edited by hmartin025 (6/28/2014 10:46 AM)

The radiator keeps puking water. The level will go below the top of the tank. The guage  will then run to 3/4. I keep adding water to keep it from over heating. It runs OK on long trips. I drove it 868 miles from Nashville TN to Saint Petersburg FL. It was much cooler in March when I made the trip. The gauge never moved until I reached Gainsville. The car runs terrible and oil pressure drops once temp is half way. You can feel radiant heat coming through the fire wall. I drive 20-30 minutes to work every day in heavy traffic. The car pukes water and hisses every time I park it after driving in the heat. I believe the 3 row radiator and a better fan will keep the car cool in heavy traffic.
I bought the car from my uncle, he bought it new! He claims it never ran hot with him. It took him 48 years to put 107,000 miles on it. He never drove it much. Mostly sat in the barn outside of Nashville, TN! Country driving is different than city driving. I doubt he ever sat in 45 minute traffic with 100 degrees outside.
MS...thanks for your advise!

Have you actually verified the temperature with a thermal gun or a real mechanical temp gauge?  Checking the top tank temp against the lower temp and checking side to side may tell you something...like is the rad plugged up.  My 5.0 in a 66 runs right near the 194 degree stat at 195 -200 on top and just under 150 leaving the rad at the bottom.  I have a two-row 20" aluminum rad, seven blade clutch fan, coil in the lower hose and a proper, home brew shroud.  The stock gauge runs just over the half mark and stays there no matter what.  Idleing with AC, running 80 with AC, climbing Pikes Peak in July with AC on. 

If it's really getting hot when the ambient temp comes up, you may have a bit too little rad or plugged tubes.  If you do move up a notch with the radiator, I also recommend a good clutch fan, a proper (that means you make one that fits correctly) shroud, and make sure the lower hose isn't collapsing.  You may consider going to a 20" rad also...aluminum.  It does require a bit of cutting on the core support but totally worth it in my opinion.  To me, just having enough cooling system to make "not get too hot" in normal conditions isn't good enough.  These things were marginal when new so I think you need to over build it.  I like the fact that I rarely feel the need to even look at the temp gauge...just like a new car.
B

Using a small mirrow and strong flashlight look across the top of the tubes to see if any debris is visable at top of tubes. If a tube is stopped up with chunks of rust and etc. is usually visable. Of course drain coolant first! LOL
Howard

Last edited by hmartin025 (6/29/2014 8:02 AM)

my suggestions are these: 3 or 4 row rad ( I run a 4), 17" 7 blade flex fan,( summit) fan shroud is a must, even if it's a crappy one, ( if you don't use a shroud, how far is the fan from the rad) proper fan placement of the fan in the shroud, blade half in, half out, 180' thermostat, make sure there is a spring in the bottom radiator hose, anti collapse. I personally don't care for the clutch fan setup, ( that's just me) I like the direct setup. This is pretty much the setup I use on a 68, 289 4bbl. auto and it works really well. It gets plenty hot in N.Y., and I've been stuck in ugly traffic on bridges in july, just staring at the temp gauge ( out of habit I guess). it worked out well, good combo. I hope this helps. Good luck!

I have an aluminum rad in my 66 with a 289 with a 6 blade fan (not a flex fan) no shroud and I have no over heating problems. Even with the original rad it ran cool. I'm in southeastern Virginia and our summers get as hot an humid as they do in St. Pete (we come to Treasure Island once a year). I did add a manually controlled pusher fan only because I got it for nothin'. Thought I might need it while waiting for draw bridges but haven't needed it yet. I'm thinkin with a 48 year old car that spent that much time sittin the rad change would be a good idea.

While I normally agree with Mustang Steve on almost everything, I have to highly disagree with the comments that "stock configuration has the needle at about 5/8 travel when at normal operating temperature" and that "3/4 of the gauge is nothing to worry about". 

Of all the Mustangs my dad and I have owned, two 66 models and a two 67 models, all have been at normal operating temperatures between the T and the E on the gauge.  Yes we live in Dallas, and this is the norm for our cars.  IF they have a experience a problem and the needle reaches the 3/4 mark, they are indeed in a situation of much concern. 

This has been our experience with four cars with the original stock gauges.  It is something that we can depend on with these cars, just like the Ammeter not working at all.

To address the problem that My66stang is having, he might consider checking the timing and confirming that the vacuum advance is working properly.  I had an experience one time on the highway where the little c clip that retained the vacuum advance onto the advance plate in the distributer came off while I was driving.  There was an immediate loss of power and the engine temps shot up pretty fast.  Just saying that timing can cause a lot of the problem as well, especially if the cooling system has previously done its job.  Also the fan shroud should be considered a "must have" item.

My66stang:
     Sounds like what you have is good, 3 row and shroud. Thefan half way out of the shroud sounds good as well. I would probablly upgrade to the flex fan if you can afford to at this time.

Lots of good info here.

*Pressure test the system
* Fan shroud all the way
*Check vacuum advance for leaks/ proper operation

Particularly the timing. If you're initial is set at the factory 6* BTDC and are running ported vacuum to the distrubutor you're not getting the power and fuel efficiency potential that 289 has, and are taxing the cooling system by generating all that wasted heat energy in the process.