I am running the stock 16” radiator . I resisted the 24” for a while now.... but I hear a lot of voices about to say “I told you so” ... lol cause I stuck with the 16” :: spent money on aluminum and electric setup..

Will a 16” can be enough for a 24” radiator?

This AC hose is my biggest hinderance i think in that install if I had to go for it

It sucks that you are still having cooling issues. When it comes to radiators for old cars, I like the philosophy of "some is good, more is better, and too much is just about right!!!"

GPatrick gives a lot of good info. For air flow, I will add that is not just through the radiator. All of the heat still needs to push out from underneath the car. Since these shock tower cars are tight in the engine compartment which can hamper air flow, some of the guys with big blocks will install a spacer (stack of washers) under the hood hinges to create an escape for the heat at the back of the hood. It’s a band aid fix that might get you through the hottest part of the year. If the rubber gasket that seals the back of the hood to the cowl is still in place, remove that too.

The primary reason I chose the Shelby hood for my car was the "fish gills" as they have been called. It amazes me how much heat escapes through them.
 

24” radiator with correct shroud and 17” fan. The extra trans cooler is a good idea. When Gary states something like that, you can bet he has done his homework. Same with my suggestion.

Your old block likely has alot of rust in the internal coolant passages. Rust will not transfer tge heat as efficiently as good clean metal.

This raises an interesting question that I’ve been thinking about as I follow this thread. How much radiator do you need if everything is functioning properly?

I installed my engine and ran it in the car for the first time a few weeks ago. I haven’t  driven it out of the driveway and most of the time it ran it was idling. Temp on the gauge warmed up to 195 fairly quickly, but never got hotter than that. Infrared laser said the temps at the t-stat housing were actually a lot less than 195.   Right now I’ve got a 2-row 1.25” tube aluminum std 65-66 sized rad, with a 180 t-stat, Derale fan in front of a 450hp 347. No a/c and the climate is cool- never hits 90s except peak summer (July/August).

I haven’t even driven the car yet (I know I should before making any decisions), but I’m already thinking I screwed up by not going with the 20” or 24” rad from the get go.  If I decide to go bigger,  will a 20”’ be enough or should I just bite the bullet and jump all the way to a 24”?

I've got to echo what everyone is saying.  220 isn't overheating, just hotter than you may like.  A 180 degree t-stat doesn't mean the engine will run at 180 degrees, just that the t-stat opens at 180.  I would run a 16psi radiator cap if you aren't already, and at that much pressure you will not get coolant boiling until about 260 degrees.

Any time you have an automatic an external cooler is a good idea.  Trying to keep that tranny fluid cool is just one more burden on the cooling system. 

I also agree that the poor running you experienced was more a case of the ambient heat affecting the fuel system than the engine getting too hot.  Most likely you were getting the ethanol in the fuel boiling and the engine having a tough time trying to ingest a fuel that was now 10% gaseous instead of liquid. 

One thing to consider is that the water pump may be moving the coolant too fast.  High flow pumps work great if you need them.  If you don't they can actually move the coolant through the radiator too fast and it doesn't have enough time to reject the proper amount of heat to keep its temperature where it should be. 

I placed mine after radiator transmission cooler.
I used a small heat exchanger.
Take a look at trucks with tow packages.
Most have both..at least from my observation.

In the wintertime the radiator "cooler" serves to help heat up the transmission more quickly.  You don't want to bypass the radiator cooler in most cases.  As mentioned, install an auxiliary cooler after the radiator cooler and then back to the transmission.  You will need to confirm but I am relatively sure that the AOD fluid line out is the upper fitting and the "in" is the lower fitting - exactly opposite of the 4R70W.  Its good insurance after the time and effort that you put into your AOD rebuild.

There is a long running myth that faster flow reduces cooling.  There are some half-truths - if you remove the restriction of the thermostat, flow will increase but you hare not holding the fluid at a higher pressure inside the engine and some critical areas will not have sufficient contact or pressure to transfer heat and even with the higher flow you can still have steam pockets or localized boiling.  So, increasing flow by removing the thermostat is not going to work.  If you increase flow by spinning the water pump too fast, the pump will act less and less like a pump but fast is around 7000 rpm at the pump.  So even if you run an overdrive pump pulley combination, you are not likely to see that 7000 at the pump in highway driving and street traffic.  There is pretty good article here http://www.pirate4x4.com/tech/billavista/Cooling/    that explains a lot about cooling in general.  It is a little marketing oriented but still good info.  Scroll down to "myth" and you will see a detailed write-up about flow.

So, after all that, before the 24" radiator install you may want to look at your current pulley ratios and see if you can speed up your water pump.  Alternatively, you could install a FlowKooler pump.  It has an improved impeller design that will increase flow for the same engine rpm.  If you think about your problem, you are getting off of the highway and two things happen - you have less airflow through the radiator and the engine is spinning slower.  You can't do much about air flow but you can spin the pump faster.  A good pump is relatively cheap and will work with any ultimate decision you make on a radiator.  Stewart Components is another source for high flow pumps.  If you decide to go the pump route you should probable speak directly with the manufacturer to make sure you are getting the right pump for your engine combo - direction of rotation, hose placement, etc..  More fun reading -  https://www.flowkoolerwaterpumps.com/pages/why-flowkooler-hi-flow-pumps-end-overheating  

Consider playing around with your antifreeze percentages.  Antifreeze does raise the boiling point (and lower the freeze point) but it makes the fluid less efficient in removing heat.  The higher the concentration, the higher your coolant temperature will end up.  But, it is usually what provides corrosion protection so you can't necessarily run without it.  So, you may consider a product called "water wetter" that helps with heat transfer and for the spring, summer, and fall in Texas you could probably run a 25% antifreeze mix.  The first link I posted has some good info on this.

Messing with your antifreeze and getting better flow may get you at or under your target temperatures.  If you have a lower profile air cleaner that hugs the carb you may find that a slightly taller version may help get hot trapped air away from the carb that will help with some of the poor running characteristics you are experiencing..

GPatrick wrote:

In the wintertime the radiator "cooler" serves to help heat up the transmission more quickly.  You don't want to bypass the radiator cooler in most cases.  As mentioned, install an auxiliary cooler after the radiator cooler and then back to the transmission.  You will need to confirm but I am relatively sure that the AOD fluid line out is the upper fitting and the "in" is the lower fitting - exactly opposite of the 4R70W.  Its good insurance after the time and effort that you put into your AOD rebuild.

There is a long running myth that faster flow reduces cooling.  There are some half-truths - if you remove the restriction of the thermostat, flow will increase but you hare not holding the fluid at a higher pressure inside the engine and some critical areas will not have sufficient contact or pressure to transfer heat and even with the higher flow you can still have steam pockets or localized boiling.  So, increasing flow by removing the thermostat is not going to work.  If you increase flow by spinning the water pump too fast, the pump will act less and less like a pump but fast is around 7000 rpm at the pump.  So even if you run an overdrive pump pulley combination, you are not likely to see that 7000 at the pump in highway driving and street traffic.  There is pretty good article here http://www.pirate4x4.com/tech/billavista/Cooling/    that explains a lot about cooling in general.  It is a little marketing oriented but still good info.  Scroll down to "myth" and you will see a detailed write-up about flow.

So, after all that, before the 24" radiator install you may want to look at your current pulley ratios and see if you can speed up your water pump.  Alternatively, you could install a FlowKooler pump.  It has an improved impeller design that will increase flow for the same engine rpm.  If you think about your problem, you are getting off of the highway and two things happen - you have less airflow through the radiator and the engine is spinning slower.  You can't do much about air flow but you can spin the pump faster.  A good pump is relatively cheap and will work with any ultimate decision you make on a radiator.  Stewart Components is another source for high flow pumps.  If you decide to go the pump route you should probable speak directly with the manufacturer to make sure you are getting the right pump for your engine combo - direction of rotation, hose placement, etc..  More fun reading -  https://www.flowkoolerwaterpumps.com/pages/why-flowkooler-hi-flow-pumps-end-overheating  

Consider playing around with your antifreeze percentages.  Antifreeze does raise the boiling point (and lower the freeze point) but it makes the fluid less efficient in removing heat.  The higher the concentration, the higher your coolant temperature will end up.  But, it is usually what provides corrosion protection so you can't necessarily run without it.  So, you may consider a product called "water wetter" that helps with heat transfer and for the spring, summer, and fall in Texas you could probably run a 25% antifreeze mix.  The first link I posted has some good info on this.

Messing with your antifreeze and getting better flow may get you at or under your target temperatures.  If you have a lower profile air cleaner that hugs the carb you may find that a slightly taller version may help get hot trapped air away from the carb that will help with some of the poor running characteristics you are experiencing..

Thanks for that. I will be playing with this setup till winter when I will decide and start on the 24” setup. I know after doing a trans rebuild and R&R I can do a radiator . It’s not the same but it’s not more difficult .

I already have the flowkooler  pump .. I am about to start recurring the distributor .. in the mean time I will also make sure I am ideling a bit high with AC on so I have enough water flow ...

I am going to give me existing setup a good old chance , and if it fails to keep things where I want them with AC on, then it’s all coming out and 24” is going in with the recommended shroud and all.

Transmission cooler is another issue .. I am trying to figure out where I can put it ... I don’t want to custome make any tubing now and then have to redo it all in winter it I go with 24”

Trans builders had said if you don’t use car for towing or racing you don’t really need a trans cooler but this is more to reduce work on the enfine’s cooling system so I’ll add it come winter

GPatrick wrote:

So, after all that, before the 24" radiator install you may want to look at your current pulley ratios and see if you can speed up your water pump.  Alternatively, you could install a FlowKooler pump.  It has an improved impeller design that will increase flow for the same engine rpm.  If you think about your problem, you are getting off of the highway and two things happen - you have less airflow through the radiator and the engine is spinning slower.  You can't do much about air flow but you can spin the pump faster.  A good pump is relatively cheap and will work with any ultimate decision you make on a radiator.  Stewart Components is another source for high flow pumps.  If you decide to go the pump route you should probable speak directly with the manufacturer to make sure you are getting the right pump for your engine combo - direction of rotation, hose placement, etc...

My experience with Stewart water pumps:  I’ve put them on two Mustangs. My old ‘86 GT and my 1992 LX 5.0. Those pumps, even the Stage 1 pumps, flow way too much. You need holes drilled in your thermostat to relieve the pressure they create. It will take forever for your car to reach operating temp in the winter. This is probably great for your drag racing Mustang but not for the street. Back to the pressure issue, every small hose and gasket (old ones, mind you) developed leaks one by one.  The weak links kept breaking. I’d fix one and the next one would give. Even the timing cover to block gasket leaked. So after finding all the problem areas and fixing them, the impeller breaks. True story: Two days before Thanksgiving 2017 I’m on the I-5 freeway near Burbank on my way to pick up my aunt to bring her to my house for a Thanksgiving. I pull up behind a beautiful 1970-ish Porsche 911. It’s green with gold lettering and emblems. The driver was going 60 when everyone else was going 70 so as I pass I noticed the driver was Wayne Carini from the Chasing Classic Cars show. I like that show so I wanted a picture of Wayne. Just as I grab my phone I did a glance at my dashboard (safety, ya know) I noticed my temp gauge was pegged! All the way up past the red line marked 270. Aaaaaaah! Just then Wayne pulls off at Lankershim and I lose him. To make a long story endless after a 200plus mile trailering home, the culprit was broken spot welds, ONLY 4! And blade do-hickey had separated from the shaft. No more Stewart water pumps for me.
Higher flow pumps are fine. Just not Stewart’s for the street.

I've run trans coolers both ways, through the radiator and bypassing it completely.  It does help in the winter, but in the summer it can cause issues.  The ideal would be a thermostatic valve that directs it through the radiator when its cold outside and around it when its hot.  Modern vehicles are using systems like that.  Adds another degree of complexity though.

If it were me I'd bypass the radiator because the car is much more likely to be driven when its hot out than cold, at least for me. 

Would you agree that after following this I think I need to get rid of my high flow water pump to better manage my cooling system? I installed it because my engine is a 351W that I had bored and stroked to 416 c.i. I installed it thinking that it would help it run cooler. From what I am reading here I need to slow the flow. In the winter it does take a long time to warm up. In the summer it heats up more and more the longer it is driven. Coming home from the bash it would get right on the edge of hot. I turned off the AC and it cooled down to the middle immediately then I turned the AC back on and the temp would work it's way back to hot again. It would run through that cycle in about 45 minutes to an hour so it wasn't a big deal but annoying and the compressor started making noise to warn me.