What exactly prevents a DC radiator from fitting on a DA?

Would like to use a DC koyo on my DA, since fluidynes are too $$$

 

the pegs on the bottom are way off, the DA ones are closer together, you could re-weld new ones on but the DC rad is taller and the upper hose outlet is off , i tried to put a my old DA fluidyne in my DC, but just bought the DC fluidyne, i didnt wanna mess with all that stuff. i have a DA fluidyne for sale its in mint condition i need to get rid of it so i will let it go for cheap.