Installing a F-Body Radiator

The old ratty radiator in my '65 Dart decided to give up. The upper radiator tank had fractured and JB Weld just wasn't doing it anymore. So it was time to replace it. I also wanted to increase the capacity of the cooling system. It was my understanding that a F-body radiator would work in the A-body, so I picked up an OE radiator from the local pick-an-pull for the old girl.

At some point in time, another person had replaced the OEM radiator with one from a '71 Duster. At least that whats the yellow "junkyard" markings said. It had been hacked on so the lower bolt holes would align with the radiator support in my '65.

The radiator mounting points on a '65 Dart measure out at 24x11.5". The mounting points on a \6 F-body measures out at 24x15". The top slots are located in the same position between the two. The radiator that I got had a surface area that measured 18x18" with one core row. The top inlet tube measured 1 1/4" and the bottom outlet was 1 1/2". The top inlet was about 1" farther to the left then the Darts current radiator.

Initial fitting showed that the radiator would fit in the chassis just fine. I had to measure down from the top slot 11 1/2" and over 5/8" from the outside edge. At this point I drilled a 3/8" hole. This gave me some wiggle room for adjustments.

While at the yard, I had also picked up a 5 blade factory flex fan and the 2" spacer from a F-body with a \6 and A/C. Initial installation of the fan with the 2" spacer, placed the fan too close to the radiator. The outer edge of the fan would nick the right and bottom of the radiator. A 1" spacer would place the fan to close to the dampener. So I settled for a 1 1\2" spacer. This places the fan about 1" from the radiator with plenty of clearance from any surrounding items. When doing final installation, I used a '77 Aspen upper radiator hose and the bottom one did not need to be changed.

After final installation, the car warmed up and everything appeared to be working OK. But a week of driving showed that something was still wrong with the cooling system. It appeared that the pick-an-pull radiator was partially blocked and had slight leaks. A can of Bars Stop Leak managed to stop the leaks and completely plug up the radiator. Sigh...

So it was time to regroup and start over.

So I browsed over to and looked up radiators for a '77 Aspen. They had one that was a HD A/C radiator for \6 vehicles. This radiator had a surface measurement of 18x22" with a 1 1/2" top inlet and 1 1/2" lower outlet. Since the web site is a front end to the Shucks warehouse, I had the option to send the radiator to the local store or to my house. I choose my house and 4 days later it arrived and I also saved $30 on the in-store price.

When I unpacked the radiator, I noticed that it had two sensors points on the upper tank, a lower transmission cooler and two core rows. The outside frame was slightly narrower then the OE radiator. So I had to measure 11 1/2" down and 1/2" over to drill the lower holes. Once again I made a 3/8" hole.

Installing this radiator was fairly straight forward. I needed to use a upper radiator hose from a '77 Aspen with A/C. The upper inlet was 2" farther over to the left of the old, original radiator. I also installed a 3x10" overflow tank that I purchased off eBay. I put this tank in the area that used to hold the horns.

This radiator fills the radiator opening on the Dart and I don't think you can get a bigger one on the Dart. A similar sized radiator for a 360 powered A-body is basically the same thing as the F-body radiator that I used. The biggest difference is that the lower outlet is 1 3/4" as compared to the 1 1/2" needed by the \6.

Initial driving around shows that this radiator is working correctly, with the temperature gauge never going over the 1/2 way mark. But the water pump has decided to spring a leak. I guess 26 years of service is good enough...

I Replaced the water pump with a GMB replacement pump. The old pump was OEM Chrysler with close to 200,000 miles on it. The new pump had 8 fins on the impeller while the OE one had 6. I also used a lower radiator hose from a '75 Dart. Everything bolted right up. I wonder if this GMB pump will have the same lifetime.