The 1964 – 1967 GTOs are some of the most difficult cars to cool. That isn’t by design, rather by all of the old wives tails and gimmicks people have applied to the Pontiac V8s over the years. Since Pontiac V8s, especially 400s and 455s, are some the most difficult engines to cool.
As such, they are awesome BS detectors for cooling system gimmicks and your temp gauge will quickly tell you the truth.
What makes the 64-67 GTO vintages so difficult to cool? A couple of things. For one, they are Pontiac V8s which by their nature make them difficult to cool. The other is because where the filler cap is located. If you’re expecting the crossflow-is-more-efficient rant to follow, then you’re in for a surprise.
The infamous ‘a cross-flow is more efficient’ myth. That’s a myth some of the radiator companies (and the Summit catalog who caters to dumb-dumbs) propagated before they had the ability to make down-flow radiators. Therefore, the only way they could sell you a radiator is to sell you a crossflow! Because that’s all they were capable of making!
The 1964 – 1967 GTO radiator is a down-flow radiator, which simply means the tanks are on the top and bottom of the radiator and the coolant flows from top to bottom. Versus a crossflow radiator, where the tanks are on the sides and coolant flows across the radiator. Hence the name. Typically the hot coolant enters on the drivers side and the cooled coolant exits the radiator on the passenger side.
So what is the half myth? Well, back in the day of copper/brass radiators, down-flows were typically made with thicker materials and liberal amounts of solder were used in their construction. This resulted in a less efficient core.
This DOES NOT APPLY TO ALUMINUM RADIATORS! That is where a lot of the radiator companies have taken this and used it as a sales tactic that has no bearing in the modern aluminum radiator age. There are countless modern examples where high efficiency down-flow radiators are employed, like the 2010+ Camaro.
The only advantage of a crossflow radiator over a down-flow radiator, in the modern aluminum age, is the location of the filler neck. On a crossflow radiator, the radiator cap is typically on the ‘cold’ side of the radiator. On a down flow radiator, the cap is on the hot side of the radiator.
Since the pressure is higher on the hot side of the radiator, the cap is going to open and close more. This can allow air to enter the cooling system over time.
The fix? Simply run a higher pressure cap on your down flow radiator. We do this for you. All of our downflow radiators have a special billet filler neck that will only accept a 16 PSI or higher filler neck.
– 2-rows of 1-1/4″ cooling tubes
– Dual 11″ HPX fans for a total 3000 CFM
– Precision TIG welded construction
– Billet CNC machined filler neck
– Heavy duty plate transmission cooler
– Stainless steel hardware
We’ve worked with a lot of Pontiac V8s over the years. Through working with Pontiac customers, we only make our GTO radiators in 1-1/4″ tubes with high powered fans to match. As such, we GUARANTEE our radiator will cool your Pontiac. If you’re sick and tired of your Pontiac running hot, we will end that frustration for you. So you can enjoy your Pontiac like it was meant to be enjoyed.
Note: The GTO and Lemans came with two different core supports. Most GTOs came with a core support for the 17-1/4″ core height radiator (22″ overall radiator height). Most Tempest and Lemans cars came with the 15-1/4″ ore height radiator (20″ overall radiator height).
All cars with factory A/C use the 17-1/4″ height core radiator. If you’re not sure, just drop us an e-mail or give us a call and we will figure out which radiator your Pontiac needs. Select the radiator height for your GTO along with the transmission type from the drop down box below.
For fan control, use our RH-02 relay harness made specifically to work with our cooling fans.
Questions? Call us (773)669-6573
Please note all GTO radiators are custom built for you. We will contact you after you place your order to make sure your GTO radiator is EXACTLY what you need for you Poncho.