radiator opening

If you get a 26" crossflow radiator the actual core dimension is about 4-5" less because it's stated width counts the tanks. I have a 68 Cuda and measured it up and a 26" crossflow radiator doesn't even take up every bit of the opening side to side. Top to bottom is just a little shy of the radiator core but not much. Most radiators list their core size so what I'd do is measure your opening and compare it to the radiators your looking at.