[LET]

I have a67 GTO i am restoring. The core support is rusted at the bottom, my car did not come with factory air. I am adding air conditioner from Classic auto air. So i need a 17" radiator. I bought a used conversion from ebay. There was NO radiator on the car i bought. Anyway, the conversion bracket came and it looks like it's the same size as my original. So i measured my original core Support and it was 20 " from the top of where the radiator sits on the bottom, to the top of the core support. So maybe it had a 17" radiator in it before i bought it. I've searched but i can't find the dimensions of any core support. Can someone please tell me how high a 67 GTO core support is. Height of core support for a 15" or 17" either one is all i need.
Thanks
LET