Bongo Fury

Hello , I am going to test the head gasket with a test kit, the one that changes colour for emissions in the coolant. Do I put it in the the radiator or the header tank any replies would be welcome. Thanks

Do it in the header tank....but be warned......if it shows positive (gases in the coolant) then the head is cracked (almost never just the gasket)
But......if it shows negative it is often inconclusive and the head is still cracked.....the cracks are so small and the head needs to be well hot to leak the gases.

Thanks for the info