Why can't I find a radiator

$80 for a used unknown if it works on ebay http://www.ebay.com/itm/1965-65-DOD...Parts_Accessories&hash=item27c8659b31&vxp=mtr

or...

$165 for a new one on ebay... http://www.ebay.com/itm/1963-1966-C...r:1965|Model:Dart&hash=item41678a5b79&vxp=mtr