22 or 26 inch radiator

I have a choice between a 22 and 26 inch radiator for my 318 Duster project. Same price, $50. The 22 is 40 miles away and the 26 is 140 away. Both guys say they came out of their Dusters. I'm reading up and finding that early 318 cars have the 22 and the later cars with 360's have the 26."
i have a 70 Demon 6, 70 Duster 318 and a supposed 74 Duster 360 yet all the openings measure the same 22.5" wide. The Demon has a 22 in, the 70 Duster has a 26" screwed in with some self tapping sheet screws which doesn't seem right some I'm thinking it should be a 22. The 74 looks like even though the opening is the same size it looks like it has factory mounts for either one.
Long story I know... I'm putting a 318 in the 74 and am just wondering if the 26 from the 70 is a better choice in the 74 and put the "new" 22 in the 70? Or...the "new" 26 in the 74?