One quick trick. Dump your coolant, flush and put one bottle of Redline Water Wetter and straight water.
We dropped 15 deg doing just this.

https://www.redlineoil.com/waterwetter

I thought I would tell you what I used on my 63 Sport Fury with my 440/493. I am on a tight budget so I use an Afco aluminum rad I got from Mancini along with my aluminum waterpump and housing. But since money was tight I went to the salvage yard and got a fan shroud from a V/6 Dakota truck that was around a 99 I believe. I modified it a little and made it fit and work on my rad and I only paid like $15 dollars for it. I used some of the plastic type holders that come in trans cooler kits that go through the rad fins to hold the shroud on. I use a flex fan with the mech waterpump also. The car works good and the only thing I did not like was if stuck in traffic for an hr or more it could creep up close to 200 so I put an electric pusher fan in front of the rad also on a toggle switch. And if I have to sit still real long in very hot weather I can hit the electric fan and it keeps it at 180 to 190. Once moving I can switch the electric fan back off. But the shroud from the Dakota truck that I made work saved me a lot of money on that as some of them shrouds can run $300 and more. I run about 21 degrees initial timing and 36 total with no vacuum advance since my dist is a race type and has no vacuum advance. I also have my waterpump bypass hole plugged and modified my thermostat and cut openings in it so water flows to the rad even when its shut. Good luck and I would definetly add a shroud to yours. Ron

Another pic of my shroud. You can also use a longer spacer and put the fan a bit closer to my rad which I did later. Ron

That's one nice looking shroud. If you don't mind can I ask what brand it is or who made it and what it cost ? Thanks , Ron

It's just the Northern aluminum shroud kit that came with the radiator.

Ron - what are the dimensions of your rad? I've got a universal cross flow in my charger and have been looking for a shroud that is 'close enough' to adapt to fit.

I would swap out the water pump, if it is the one with the cast spiral impeller. Get the GMB aluminum replacement water pump. It is the same one Milodon sells minus the plate. You can make a plate or buy one cheap.
https://www.summitracing.com/parts/gmb-120-1200/overview/make/chrysler

The 440 source pump & housing work great, it gets over 105 here in Southeast Tx, my 68 Charger 512 , COLD ac will run 180 all day long, sitting in traffic or 100 + MPH, ECP radiator 2 row, 18" 7 blade direct& a fan shroud Timing 24 initial 36 total,10 more in the vacuum adv hooked up to ported vac.

I took WP off last night the bypass hole is same size as factory one. I did notice some rust sediment. So I'm going flush system mod bypass hole get a high flow t-stat and shroud. This radiator is 20 years old so if cleaning it doesn't work a new 26in rad is going in. Thanks for all the advice. Mike

I have a street/strip 511 and use the 26" ECP radiator without core support mods as well. nice piece. I use a shroud from jegs that is a 69 charger replica with a flex a lite alum/steel fan and mechanical milodon hi volume pump. No thermostat and evans coolant. Cools fairly well. On a 85* day about 190* was normal water temp until i mounted an oil cooler to the front of the radiator. Now 195* and at 90*+ day 200-205*. I dont usually drive the car at any thing over 85* air temp anyway. The shroud from jegs is a nice piece and fits real nice as well. Oh, one other thing. My block is filled with hard block damn near to the deck. Hope this helps

I will check into that shroud. I got to looking at my radiator and think it is time to replace with a 26 in ECP unit. Thanks again

I used a 68 camaro shroud on a crossflow Afco ali radiator in a 65 plymouth

Tex

I will have to measure it as its been in there since 2010. I got it from Mancini and I told them it was for my 63 and the guy knew which one would fit. But I forgot the exact size so I will try and measure it tomorrow. Ron

Couple of things that don't help your temp-situation;

No vacuum advance at idle
New engine build
Old radiator + Rust sediment

-

Newly build engines always run hotter than seasoned engines.

If your cam/engine vacuum is mild enough, you'll want vacuum advance connected to the intake manifold.

I'm pretty sure there's quite some rust and scaling inside your cooling system.
This won't be removed by regular flushing.
You'll need a mild acid to dissolve the rust and scale.

I just had a similar issue with a 496ci stroker engine in my '60 New Yorker.
Engine has an older Mancini alum. waterpump and housing.
The car would run hot on the highway and hardly come down again at slower speeds. Found the (old/stock) 3-core radiator had some cores blocked.

Took out the radiator, flushed it with hot water a couple of times, and laid it flat on its back, and filled it with citric acid.
Citric Acid is an organic acid which smells nice too (it's used in about all kinds of cleaning products).
Took about 5 Liters (about 1.3 gallon).

Let it sit for a few days and occassionally move/tilt the radiator at various angles to agitate the acid and prevent sediment from setting.

If there's enough rust and scale inside, the citric acid will turn into a white milky mixture.
This means the rust/scale is being dissolved into a suspended powder.

Poured into a container the milky powder will set on the bottom after a while so the 'clean' acid above it could be reused for other de-rusting jobs.

I did 2 citric acid treatments on the radiator and the engine temps have dropped back to normal again around 160-190.

the jegs shroud is $149 and replica of 67-69 B body, but works perfect in my A body. Heres a couple pics of my combo to give some ideas. Just went for a short 20 minute cruise in 87* weather and temps were 200* coolant and 200* oil. 205* in stop and go traffic. I would like it cooler, but i'll live with it.

I would say the fan is an inch short all the way around which leaves some efficiency on the table.

i think my fan is a 17". not sure whats available for larger sizes.

i've been following this thread because I've always been chasing a heat problem in one of my cars. all of this got me thinking so yesterday I went out in the garage and done something. my 69 r/t is a problem child; all iron stock 440 with a 22" radiator. the stock core only had 76 tubes (2 row), so I upped that to 144 tubes (3 row) several years ago; not a lot of difference. last summer I went thru the engine, nothing special just gaskets, seals, but I did replace the pistons and the rings seemed to have a lot of tension. I also put in a 440 source water pump and new mr.gasket 160 thermostat. had the car out last Saturday, very nice low humidity 81 degree day, and the engine went 210F+ in traffic and stops and would never recover or budge off that 210 even when I got moving.

yesterday I took the thing apart, put a plug in the bypass (but did drill a 1/8" hole in the plug. this is very simple to do by running a 1/4" pipe tap thru the bypass hole.). replaced the 440 source pump with a 6 blade pump (larger o.d. than stock vanes) with the anti-cavitation disc, put in an ancient stant brass 160 thermostat. I did richen the idle mix a little also. started it up this morning and went for a drive. 83-84 degree morning here with high humidity. I didn't get stuck in a lot of traffic but did stop twice and turn the engine off for a few minutes. temps climbed to 210 with the engine sitting but when I did re-start the engine temps began to recover some. driving temps were a little cooler, (no 200+, about 185-190 the highest). I believe there was a real difference in the changes; not huge but enough to restore some comfort level. I believe the pump change plus the bypass plug are improvements. meaningful improvements with this car are hard to come by. it's a shame that temps dampen driving this car because it drive so nicely.


my other car is a 65 coronet; 440, alum heads, headers, small cam, ch28. it has a 22" brass radiator (former a/c car with the inlet on the passenger side) 204 tubes. this thing won't run hot if you drove it thru hell. I use a 180 'stat but, the carbs don't like much heat (heat transfer from heads to intake manifold). ironically the r/t's stock avs doesn't seem to be affected at all by the heat. two cars are as different as dr. Jekyll and mr. hyde.

Lew, you should try either a real “high flow” thermostat, or drill a few 1/4” holes in the one you have.

You shouldn’t try blocking the bypass in the housing without there being some other means of bypass available...... which would be the heater core.

As another experiment, along with drilling holes in the stat, you could try plugging(not looping) the heater hose fittings and seeing what(if any) impact that has on the temps.

With the bypass blocked, and no heater hose bypassing(the holes in the stat become the bypass), all the coolant is pumped through the radiator.

I do have a high flow thermostat. I do run a heater, so are you suggesting keeping flow thru the heater core with the bypass 90% blocked? what are the effects of not having a bypass and flow to the heater core closed off? I almost did the bypass thing last summer but wasn't sure about the effects. all I know is there were some positive effects from using a traditional type pump and bypass restricting. upping the learning curve here. very helpful comments/posts.