I also ordered a 16 inch electric fan but it probably wont fit with the shroud that I am currently using. If this doesnt work then probably start looking for a new bottom end.

you will not need the original fan shroud with the electric fan.

 

Well problem finally solved. Bought a 4 core aluminum radiator from "Monsterradiators" in southern california/ Supposed to be a drop in replacement. Didnt fit. Had to cut about a 1 inch square out of the radiator support and slide in the radiator on the front side of the radiator support then add spacers on the top. The radiator was purchased with a 16 inch fan and just barely fits. I now have a northern 2 core radiator if anyone is interested that I will sell cheap.

The mustang with my .040 over engine will only heat up to just under 200 degrees.

 

Well I thought that I had the problem solved but driving in traffic on a really hot day the car overheated. It just keeps creeping up very very slowly until it gets hot. I put in a 16 inch 3000 cfm fan and a monster radiator and it still gets hot. The only thing left is I guess to pull the heads and see if the steam holes in above cylinder 1 &5 were drilled by the engine builder. That is the only thing that I can figure to check.
Have done: Timing ( 0-12 degree increments), fan(14 to 16")radiator(stock, 2 row alum, 4 row alum), pulled plugs( all great),Compression check( all within 5 ib) different thermostats( ended with 180 degree), looked for oil in coolant,

Is this typical of not having the steam holes drilled or a head gasket leak???

 

I'm half way thru the Edelbrock 2091 head/cam install on my 289 and I have read everything I can find on this steam hole topic. The sources I have read all say the same thing, if the steam holes are not done the result is exactly what you have, slowly rising temps despite any radiator/fan changes. It can also happen with head gasket(s) installed backwards, meaning the front of the gasket (no water jacket holes) is not front of the engine, so coolant isn't forced to the back of the block before coming back up front through the heads. Again, slowly rising temps no response to bigger radiator/fan. Please post what you find, but FWIW I think you need to check your head gasket install and see if the #1 and #5 steam holes were drilled

 

I fought heating issues for years and spent A LOT of money because everybody was an expert. I now have a Northern raidator that goes frame rail to frame rail,Taurus fan and a Meizere 55 GPM electric water pump. The hottest its gotten while moving in the past weeks has been about 200 and will idle all day at about 180-185.

Things i have tried
Be Cool replacement raditor
twin puller/pusher 16" fans
Brassworks Flowkooler water pump
Water Wetter
External trans cooler
all of this got it rungreat on the freeway but would idle at 220+ and sometimes even reached 240+.

 

Do you have any accessories like a tranny cooler, oil cooler, or a/c condenser installed? If so, what is their relationship to the radiator? Like I said before, air needs to be able to zip right through the fins of all of those coils. If the is an air gap between coils or the coils are not installed perfectly vertical and parrallel to the radiator, you will have air flow problems. If the fan is not pulling enough air or if it is hard to pull air through the fins, you cannot get enough heat exchange. That is why I tell people that an electric fan is not usually necessary. Typically if you overheat in traffic but are great on the highway, you have an airflow problem. This can usually be fixed by improving air flow patch through the coils, installing a fan that covers 70%+ of the radiator, and having a properly fitting shroud.

I see from above that you do have an a/c condenser coil. Since you have already dropped a ton of money and time in buying new radiators, fans, thermostats, etc, they removing the other coils like the condenser. Hold a rag to the front of the radiator with the engine running and fans one. If it holds in place with no problem, go for a slow drive in traffic and see if it does not behave better. If it does, you have an air flow path issue.

That is what I had in my '69 and changing the condenser coil mounting angle and installing a killer 19" flex fan took care of all my heat issues.

 

The fan that I have installed pulls a ton of air. It would have no problem pulling a rag or paper into the front of the radiator and holding it there. It takes a really long time to heat up( around 45 -1 hour ) but just doesnt seem to cool even on the freeway or at a decent speed.

 

I don't know man. If you say there is good unobstructed air flow and good coolant flow your cooling system should be ok. One more thing to look at. What is your temperature differential between the inlet and outlet of the radiator? You can find this will an IR Temp gun. If the coolant flow and air flow are good, you should get 20* difference or preferably more.

 

Searching forums due to a similar problem as 4R RUSH. First I will start off with suggestions for 4R RUSH that I didn't see in the forum; what kind of headers do you have? I had shorty headers and switched to tri-y's. That got some of the heat out of the engine compartment. I went to a 2 - 1" core race radiator from Northern...helped allot. I also run with steel hoses and yes, believe it or not, that helps. I have a Shelby valance = more air flow. Lastly, what type of coolant are you running? I started running Dexcool after reading a number of articles, although I have to mention that my mechanic recommended against it. He said Dexcool sometimes has gumming problems - something I haven't experienced. All of this worked at one point 3 years ago. This leads to my problem, which I will add in a separate posting.

BTW -- I have a daily driver 400 hp 65 Fastback with a 289 bored out .40, aluminum heads, comp cam, quite timing gears, tri-y headers, edlbrock 750 (I know, too much - don't ask and may be part of my problem), aluminum heads, rocker rollers, C-4 auto (I moved the cooler out of the way), Vintage Air, newly installed Spal 16" electric fan, steel hoses, 100 amp alt, etc.

 

Now for my question….Wow, how do I make a long story short -- my problem is that the engine gets hot (230-235) at higher speeds. -- Living in AZ the heat is something we have to deal with. 3 summers ago I had it all worked out. Then two things happened: 1) someone backed into me = minor damage, mostly damaging my condenser and 2) I decided to go to an automatic after my 5-spd transmission went out (I did it to cope with the traffic, but it has been the most regrettable modification I have done on the car). When the shop replaced the condenser they replaced the coolant and hoses (apparently they couldn’t get the steel ones back on – go figure). After I had the work done I haven't been able to get the temp back to normal and I have tried everything you all have discussed including moving the tranny cooler out of the way. I also went back to steel hoses and Dexcool (flushed the system at this point), which both helped. I had a 6 blade high cfm fan with shroud properly install and it would run fine as long as I was moving, but horrible at idle (235 regularly). I determined that if I kept the RPM at 2200 plus while sitting, it wouldn’t heat up over 220’ish. So I thought an electric fan would do the trick. I installed the 16” 2360 cfm Spal fan last weekend and low and behold I thought that fixed it. It now can sit for an undetermined amount of time at idle without overheating (stays around 200-210). THE NEW PROBLEM = now at 2800+ RPMs (60+ MPH) it heat to 230-235 even if I don’t run the AC. Thoughts? I think I am running a little lean, but have my doubts if that is the sole issue. Maybe too much carb? Prior to the accident I had a Holly 670 street/strip carb. Just cannot figure out why it is heating up.