I have 3 vehicles with copper brass radiators, one is 60 years old and doesnt leak, the other one was from an 84 CJ that I put in a YJ, then it went into a TJ with about 400K miles on that radiator, the YJ and TJ's plastic tanks leaked...
Well in that case, @mrblaine might need to try one of these 30+ year radiators out since it's very obviously better than any of the OE stuff.