65 Dart 6 cyl rad

I believe the 6 cylinder radiator core measures 19 inches with an extra wide radiator side bracket on the passenger side to fit the V8's 22 inch wide core support opening.

I took a V8 22 inch radiator and had the upper/lower hose nipples soldered on where a slant's would normally be found. If your opening is the 22 inch wide (and it should be for 65), that could be an option for you.