73 Scamp Rad suggestions

Hello all, I am currently looking for an aluminum rad that will fit my 73 Scamp.
Engine is 422 (340 stroker) makes 470 hp and 500 tq.
The champ rads look pretty nice not sure which part number to use though? My rad core opening is 22"x 18.5" and center to center 24" on mounting holes.
I'm also considering griffin Chevy style universal but not sure how to mount?

Any suggestions?