You can get a new 1980's Ford Escort W/AC heatercore from Autozone for $17 +tax, then mod it to 1/2" or 3/8" for about $3. This radiator is nearly identicle to a Big Mama, DD Heatercore, or DTEK Core. I am using this radiator right now and it is amazing. With a 156 watt TEC and Birdy at 1.53 it will keep my coolant a mere 2C over ambient