22-inch Replacement Rad. for six cyl.?

I'd have to look for the reciept, but when I replaced the one in my /6 '68 Dart (19"), I replaced it with one from a '74 with air conditioning (22"). I think I also used the hoses for a '74 and the placement was slighly different. Really wanted to recore the original, but more cost effective to replace it even though I ending up loosing the look of the rounded tank on the original. Bought it at Pep Boys at the time, but AutoZone, Advance, etc at the time had the same part. In the end, I think my real cooling problem was a stuck heat riser, improperly adjusted float, and distributor weights.