BB A-body Radiator

would that fit in my 64 valiant i measured 21 1/2" between the mounting holes on my rad support.car has a 273.

You probably would have to re-drill the mounting holes, the core is 22" wide. Just as long as the lower radiator hose is on the driver side with the 64' 273 I would think it would be fine. I had this in a 71' A-Body with a big block.