I have a 1972 small block with manual transmission. I splurged on a DeWitts aluminum radiator with electric fans... model 32-4139070M. My old radiator had two posts on the bottom that slid into the grommets at the bottom of the radiator core support, but I just realized the new radiator doesn't have those posts. So, I'm not sure how to mount the new radiator.

Not sure if this makes a difference, but I want to replace my core support because it's rusted and cracked at the bottom corners. I appreciate any advice you guys have.

 

Call DeWitts. They may have sent the wrong part. If you haven't installed or put coolant in the radiator, I am sure they will work with you.

 

Per the website for that part number:

Application note: This radiator was used on 1969-72 small block Corvettes equipped with factory installed options. These options could include an automatic transmissions, air conditioning, or special engine options such as LT1 and L46. Base cars (with no options) used a smaller radiator with the separate surge tank.

If you have a base engine car, you have the wrong radiator. Going through their C3 page, I found this.
​​​​​​​https://www.dewitts.com/collections/...eries-radiator

 

You should have ordered a 32-942B.

Read the fine print from their website





Options:

Call Dewitt’s and arrange for an exchange. You’ll need to decide if you can repair your existing support or replace.

Keep what you have and swap out the core support with one from Coffman Corvette. 419-522-4226. This radiator does not use the surge tank so you’ll need to replumb some hoses. Not a big deal.

 

I have the same car as yours and this is the radiator you need. IMO, there is no need for electric cooling fans.There were no electric cooling fans when these cars were new and they cooled the engines just fine. As long as you have a properly working fan clutch, radiator seals and lower air deflector you will not have any overheating problems.



I installed my DeWitts 3 years ago. Here's a photo from Sept. 2023 of the gauge cluster after sitting running on high idle, IN MY GARAGE, after 30 minutes.

 

If you look close, you can see the 2 mounting nubs on the bottom of the new radiator.

 

Not to hijack the thread, but I want to learn.. The above is the manual transmission radiators for 68-72 cars, right? This should be in an LT-1? And the normal looking radiators are for auto & AC cars? They both have different radiator supports for the different radiators it seems too?

 

I'd love to have the OP post photos of the old and new radiators. Again, to learn. What he ordered is so completely different than what every one else says he should have, I'm curious why the only question is about two mounting nubs.

Here's what the OP's link goes to.

 

My car originally came with air conditioning. Engine temp would start to rise after 5 minutes at idle and the fan was moving at idle, but engine temp would be around 210 degrees while the car was moving. A family member who works on hot rods mentioned the idea of possibly going with a unit with electric fans. So, when I reached out to DeWitts with this info and asked one of their reps which radiator to buy, he suggested the one I ordered.

I already tossed the old radiator. I don't remember seeing brackets towards the top corners to hold it in place. I could be wrong, but I think it only attached with one support at the top middle or bolts at sides. I can take pictures of the core support on my car after work, but this is what it looks like. I know it has the thin black panels that extend in from the sides.

I emailed the original rep that made the suggestion. If I don't hear back from him soon, I'll reach out over the phone. I just want to make sure I know what to ask for. The car is a cruiser. I'm not looking to race it. Just looking for it to be as reliable as possible for an older car.

 

DeWitts has a long established reputation for being a good business to deal with so stop the emails and talk to them.

You have two radiator choices when it comes to the type, 1) the type you have that utilizes a surge tank and 2) the type that does not. To me, the most logical choice for you is to stay with the surge tank type and exchange the radiator with DeWitts.

However, you have another, related issue and that is the condition of the core support. I would recommend you first decide what to do with the core support. If it is repairable, fix it. If not, replace it.

If you decide to replace it, as you already have a non-surge tank radiator in your possession, you have the opportunity to buy a compatible support, remove the surge tank, and off you go. Or, buy the same style support as you have and exchange the radiator.

Word of advice - don’t attempt to do a Bubba job of cobbling up a frankenradiator/core support combination.

 

If you can get more cooling surface, and dual Spal fans, by replacing your core support, that seems like a smart play.

The fans, though, will require wiring, and possibly a new alternator, to work properly and safely. Hopefully your Hot Rod family member can help with that. Your car will thank you, with or without AC.

 

Something is not quite right here. You stated you have 2 posts on the bottom to mount the radiator. Then in a later post you state the car came with air conditioning. GM part # 3018802 is the radiator for an A/C or LT1 optioned car. GM part numbers 3155316 and 3007436 both are radiators with 2 post bottom mounting. I'm confused.

 

upgrade your core support or look and see if the holes are already there for the saddle mounts. These later cars used the same core support most of the time and had provisions for both. You can buy the saddle mounts and you will have better cooling...you will need it of you do any upgrading to your engine at all. And all corvettes had cooling issues, you will be ahead in the game using a larger one.

Paragon lists the parts but the lower mounts are welded on, uppers bolt on

 

What he has now and what the car was built with can be two different configurations. A lot of water has flowed under the bridge in 51 years.

 

I noticed that the new radiator looked different from the old one when I first took it out of the box this summer. I expected it to look different because it had the electric fans attached and I foolishly didn't take measurements because the rep I contacted seemed confident the part number I asked about was correct. I recently stumbled across a Corvette Central article that stressed the importance of measuring and having a solid core support. That's what made me examine things more carefully.

I spoke with a different rep at DeWitts today and he was very helpful. They will allow me to return the wrong radiator for the correct one since it was never installed and I may also be able to get their recent Black Friday pricing on the new one. At first the rep was confused because his system didn't show '72 SB manuals as having air conditioning. But when I explained that my car has an expansion tank and the core support has the black inserts extending in from the sides, he said the smaller radiator with only one fan is the one that fits. He also said that since my new engine is only pushing 340 HP and runs on 87 octane, the smaller correct radiator will provide plenty of cooling. This car is my weekend ride. It allows me to relax, think about my dad, and sometimes drag my daughter along for an ice cream run in style. When I want to have a little more fun through the twisties, I'll take my GTI.

The Vette is not matching numbers and I'm pretty sure it was in a front-end collision at some point before my dad bought it. I replaced the heater core a few years ago and recently pulled out the AC coils and massive casing that surrounded the blower motor to get ready for the AC box delete. All that pointed towards a car with OEM AC. I know for a fact that it's not an LT-1, but I remember my dad saying the previous owner told him he built it up to be "like" an LT-1... whatever that's supposed to mean. Combine that with the fact that it had leftover wiring from 4 different alarms, I sometimes struggle to know what originally came on the car and what was pulled from someone's parts bin.

After reading everyone's advice and talking with the rep from DeWitts, I think I'm going to go with the smaller radiator that fits my current core support. I've attached a few pictures of my core support. I think it looks like this one from Corvette Central. Based on the cracks and rust in the photos, I'm pretty sure I need to replace it. Both bottom corners look like this. Let me know what you think. I appreciate your input.

 

Ask Corvette Central if the support is manufactured domestically. Coffman Corvettes is where I got mine from many years ago. Their website, curiously, says your application is sold exclusively by Zips and I see Zips has it for the same price as Corvette Central.

Looking at your existing support, while clearly it has rust but it’s not all that bad as it is localized (very common). Certainly have seen a LOT worse. The rest of the support looks fine. You may want to just clean up what you have, remove the rust, paint and apply some rust proofing. That will likely last at least as long as you drive the car, providing, of course, you don’t expose it to salt. A competent welder can repair it but IMO, given your situation, may not be needed, provided you stop the spread.

 

Corvette sentral lists them lists them.https://www.corvettecentral.com/c3-6...%26count%3d108..
Ebay has them
Im sure others do to
Volvette https://www.volvette.com/CL103P.html

 

The radiator core support is a major front end body support. I would buy a new one to keep the front end from sagging. The company that I worked at made these.
Coffman Corvette got the original GM dies from us to make these. Lou.

 

I just finished checking out Coffman/Zip. Zip’s website appears to have two radiator supports, but only one of them is listed as being made in the US. If Corvette Central’s core support was made in the US, I’m sure they’d market it that way. The domestic version from Zip is $80 more expensive. I’m guessing that’s the one Coffman fabricates. It’s also the only one I’ve seen with any customer reviews. Granted there’s only two, but they’re both positive.

With all the money I’ve spent gathering parts during the past six months, another $80 for what’s hopefully a better part and to support US manufacturing certainly isn’t going to break the bank.

 

Thanks for supporting US manufacturing! I'm sure Zip will confirm the source if you ask.

Since you are replacing the support anyway, are you going to use the larger radiator that DeWitts sent you as a happy accident? Or swap for the "correct" OEM style? Either way, good on DeWitts for making right with you.