txhemi840

to start off i have a 99 ls1 camaro 243 heads eps cam and longtube headers... i have to add coolant to my car quite often...when i go to the track or play a little on the street my low coolant light will come on so ill check it and it seems to all or most go into my overflow tank and then it will shot out the top of the overflow tank. any ideas on what could be causing this ive been told head gasket but oil is clean