Here is a shot of the Ron Davis radiator in my Group 4 car. Not a good shot, but too lazy to get the car out of the stacker right now to get a good photo. Dude I got the car from said he had it custom made with Ron, but who knows if that is right or not. It is thicker than the Fluidline I have in my red 5S and has a hose at the top too. Will take photos & measure thickness later when I am sober.