I e-mailed Fisher Radiator Service several months ago (Aug 29th 2002) asking about the metals in some of their heater cores. Their response was as follows
All the heaters listed below have brass tanks and the cores are made with copper.
Thanks....Don
Fisher's Radiator Service
Don Fisher
www.heatercore4U.com
2-205
2-422
2-417
2-144
2-257
2-275