273 Radiator for 340?

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71340Duster

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I've found a radiator, looks like part number 2785970. Seller says it's out of a 67 Barracuda and a 3 row. Roseville guide says for a 273, do you think this would cool a 400ish horsepower 340 (living in the Northwest). Thanks.
 
As long as its clean and in good condition it will be fine.
You'll need a shroud too.
I have the same radiator but a lower performing engine and my car runs at 180 all summer long.
 
As long as its clean and in good condition it will be fine.
You'll need a shroud too.
I have the same radiator but a lower performing engine and my car runs at 180 all summer long.

I will have new cores put in, want to get a shroud too. Fortunately I have a long time, are they hard to identify, part numbers etc.?
 
Is the car a stick or auto? My dart would run 190ish with 727 and now I can barely get 170 out of it with a 4 speed.
 
3 months later.....I wasn't able to get that radiator but I did get this one. Drove stupid far to get it, price was okay at $90 tho. I'm taking it into a good radiator shop to see if they can re-core it adding a third row. I'm wondering if there's anything else besides adding the third row that I can enquire about to make this radiator have the max cooling possible. One thing I'm wondering is about offset rows, does that get more air onto more fins and is it something that can be done with these radiators? Any ideas or comments would be appreciated again looking to cool 350-400 Hp. Thanks.

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A CAVEAT........and I'm convinced this happened to me

OLDMANMOPAR originally posted this, he claims he has found cases that make "sense" that years of thermal cycling have cracked the fins partially loose from the tubes. This causes the radiator to NOT be able to "radiate"!!!! The tubes can be brand new and flow like mad, but don't reject heat as they should

So..............the original rad out of my 67 273 WOULD NOT cool my pretty much stock 360. A rad shop claimed it should "cool anything." One day I had a /6 later model (73?) in unknown condition. Decided to swap it in "just to see". It was similar 2 core, the old 273 was round tank, the /6 was the newer square top tank.

THE TEMP IMMEDIATELY took a nosedive, obvious on the gauge and "feel" under the hood. It was DRAMATIC with no other changes!!!
 
Here's my .02 and then some.
To make that servicable, it will need a new lower nipple (fairly easy) and, if it doesn't leak, a good cleaning. What 67Dart273 wrote makes sense, so check the fin attachment. What breakstuff wrote has also been my experience - in normal mixed driving and at the strip, a standard slant 6 radiator worked.

For reliability, sure, a thorough disassembly and restoration is the way to go. The big difficulty will be the upper 'header' where all the tubes attach. Even Bob at Glen-Ray had some supply issues last year, which I believe are now resolved. But if your local shop can get the fin & tubes assembly with the header for the bubble top tanks, then rest should be smooth sailing.

Just to check the boxes before you spend $$, there are some match up issues if your 340 is using the '70 and up water pump. Assuming it has the cast iron pump, then you're just looking at a straight up restoration.

One other item that is difficult to get for the '67 radiators is the shroud. If you're making your own, then no biggy. In your location, unless the car will be doing a ton of idling, you can probably get away without one. A shroud really helps move air through the radiator when the car is not moving, and in hot weather (85 F) the coolant temperature will start to creep up.

Your other situation, when the engine is putting out max effort, topping at 350-400 Hp, will only be for 14 seconds or so. My experience is that a standard system can carry off the extra heat that's going into the coolant.

If you do get a thicker core, keep in mind there may be a little less room to the fan. I don't think it will be an issue, but best to get some measurements.
 
Thanks to all for the comments suggestions so far. I just got done dropping it off at the radiator shop. The shop owner told me his idea and showed me the materials that would be used and some techniques that would be applied. His idea is using two 3/4 inch rows of tubing. This should help with the fan spacing. He showed me the internals of the tubing, grids (small squares) that run in one direction with the next running the opposite direction. I guess this is to agitate the liquid as it flows down the tubing. In addition to that he mentioned they would do a "dimple" process, not sure on that will have to ask again about it. He also talked about fin count and could possibly be reducing that count if necessary to have more flow though.
Yes I will be using a cast iron pump, correct year timing cover etc. to match my block (even though the duster is a 71). I do live in the NW and on an island in the Puget Sound so the weather is pretty mild but I want to be able to drive it over the pass, into the dessert etc. on occasion.
 
I just had a radiator re-cored for a 70 cuda' 340, it ran me $380.
Let us know what it runs you.
 
I just had a radiator re-cored for a 70 cuda' 340, it ran me $380.
Let us know what it runs you.

Will do. I had this shop re-core and add a row to a rad for my 350 in my Chev Suburban and it was around $450, so I'll post what this radiator is quoted at.
 
Well the quote came in and it was more than I expected. Core price is $463, he gets his materials out of Langley BC. Also the labor will be 3 hours, $285 for a total of $758. Radiator comes with a 3 year warranty and a guarantee to cool my 340. Ken got into some of the details about the header, dimpling, 10 fin count per inch, blasting and painting processes, multiple pass soldering etc. It will be about 1 7/8" thick so should not interfere with the fan. This guy has built a radiator that ran in Bonneville, really small dimension because of the shape of the car, set some kind of record, great pics in his shop. I won't have this work done until Feb. and will post pics when I get it back.
 
I hope your changing the water pump to 69 and earlier style otherwise you wont be able to use that early a body radiator.
 
Wow, that's really expensive! The guy I use has been doing radiators for about 60 years, and he is in the $300 range all day long! Yes, it's driven by the price of the core, and I'll bet those custom cores can be really expensive! Never had the need for that much cooling myself, so I stick to the classic 3 row!
 
I hope your changing the water pump to 69 and earlier style otherwise you wont be able to use that early a body radiator.

Yes, will be using a cast old style, will have to get smart (like everything else for me) about which ones move enough water.
 
Wow, that's really expensive! The guy I use has been doing radiators for about 60 years, and he is in the $300 range all day long! Yes, it's driven by the price of the core, and I'll bet those custom cores can be really expensive! Never had the need for that much cooling myself, so I stick to the classic 3 row!

Yeah, probably a 2898031 or something built for a 340 auto would have been the best. Looked quite awhile for one, hard to find with inlet/outlet on drivers side. I found plenty that had already sold from $300-$450.
 
Why not just get a factory style replacement like from classic industries? I have one on my demon and my car stayed at 180 and maybe crept up to 190 in stop and go in 95 degrees. Just recently replaced the 5 year old murray water pump due to some slight play in the bearing, with much advice from the members on here i upgraded to the milodon high flow water pump paired with a milodon high flow 180 t stat and it seems much more efficient. Actually can see when the t stat opens, opens at 180 and drops to 170
 
Yeah, probably a 2898031 or something built for a 340 auto would have been the best. Looked quite awhile for one, hard to find with inlet/outlet on drivers side. I found plenty that had already sold from $300-$450.
Glen-ray probably has, or the parts to rebuild one for you. Would have cost more but come with a new core etc. Also don't judge their prices based on the rare number - dated ones. Some radiators are less, repairs are less, etc. I figured you've already commited to the local guy so didn't see any reason to mention it.
 
PS. With a soldered copper-brass radiator and heater core, be conservative and use traditional coolant with inorganic corrossion inhibitor. That's the green stuff, but not the hybrid organic acid technology (H-OAT) that is often sold as "universal". Shop carefully. None of the other stuff has particularly good protection for the solder, and generally less protection for the copper until well established.
 
Why not just get a factory style replacement like from classic industries? I have one on my demon and my car stayed at 180 and maybe crept up to 190 in stop and go in 95 degrees. Just recently replaced the 5 year old murray water pump due to some slight play in the bearing, with much advice from the members on here i upgraded to the milodon high flow water pump paired with a milodon high flow 180 t stat and it seems much more efficient. Actually can see when the t stat opens, opens at 180 and drops to 170

I want a Mopar radiator in my car, also don't want an aluminum. I'll check into the milodon.
 
My recollection is that the Milidon's big thing is the plate on the back of the impeller to reduce cavitation.
 
Here's a water pump that was thrown in with my short block, will try to look up numbers and figure out what it is.

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