Wait. What the hell are we doing here? Trying to figure out what size radiator the car had from the factory by measuring non-factory mounting holes you drilled yourself? Yeah that's not gonna work.
Where are the factory mounts? Should be pretty simple, if they're at 24-1/8" center to center it came with a 22" radiator, if they're at ~28" c-c it had a 26".
And since it's a '73 340 A/C car, it should have had a 26" radiator, so the mounts should be out at 28".
