Conversation Between LS6427 and JTAYLOR

my 2002 camaro ss over heats only when get on it. Driving around just cruising its fine. coolant spills out the overflow. i've changed t-stat 3 times rodded radiator new water pump car has been re-tuned. wat could possibly be the problem....head gaskets maybe? Its driving me crazy because i cant play with my with my baby any help would be good.