Generally speaking more surface area means more cooling, bigger cooling better. That doesn't mean the smaller one won't do the trick though.
I have been thinking about buying some sort of smaller all aluminum rad and making it triple pass. Maybe take a band saw cut some slots into the endtanks laterally and brazing or soldiering in a few small cuts of sheet metal. This would make better use of the radiators surface, in turn cooling better with less space and reducing some weight at the front of the car, and making some more room. I think it could make a good alternative to the Koyo.
I have been thinking about buying some sort of smaller all aluminum rad and making it triple pass. Maybe take a band saw cut some slots into the endtanks laterally and brazing or soldiering in a few small cuts of sheet metal. This would make better use of the radiators surface, in turn cooling better with less space and reducing some weight at the front of the car, and making some more room. I think it could make a good alternative to the Koyo.