I have a champion aluminum radiator in n my 69 valiant. It fits good. Have had no issues in the last two years. You won't be able to fit any OEM Chrysler fan clutch in it. There's just not enough room between the water pump and radiator. I put a Mercedes plastic fan blade and fan clutch on mine. It just barely fits. Only about a half inch between the fan and radiator. It works really well though. I'm very happy with it. It's cheap too(aftermarket ones, not OEM ones). OEM ones cost more than the car is worth......

Not sure this is your issue because a different radiator had a beneficial effect... but just in case anyone else is churning the mental gears, pay attention to the rust-resisting qualities of the coolant. That wears out after a while. If you end up with an (insulating) blanket of rust in all the cooling jackets, it's going to be a lot harder to draw heat away from the combustion chambers.

Simply put, a lack of ability to cool might usually be the radiator's fault, but isn't always.

- Erik

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Lots of early Valiants and Barracudas have crossed my path.
Also a handful of other toys for variety now and then.

I put a Champion in my 66 Valiant. It was pretty economical and only needed different holes drilled in the support to bolt right up. I'm pleased with it. No issues of any kind and when the thermostat opens my temp never moves no matter how hot it is outside. It stays on the cool side of the gauge. I wrote up what I did on FABO as the hoses were a bit of a challenge, you can read about it there.

https://www.forabodiesonly.com/mopar/th ... ap.359779/

Also see here and here.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Griffin has 2 lines, with very misleading naming and its led me to have fitment issues before. Their prettier ones utilize a box design that is cheaper to build and suits a lot of applications and is generally cheaper. The units that have a stamped tank design are a more stock fit, and usually cost significantly more as they are a specific design as opposed to a generic one, however they bolt right in as a stock replacement.

And oh by-the-way... Griffins are welded as opposed to glued. You get what you pay for as my old glued radiator had to be re-glued several times. VERY frustrating.