all new head gaskets call for oil change, after all , the fluid did spill down the oil drains when the head was pulled.
unless you were very very carefull to drain every thing first.
pulling inake MAN first so that dont drain to pan.
drain rad
pull block drains , or pulling the water pump will get the block dry (down to 1/2")
http://carfix.stufftoread.com/t-belt/t-belt2w.jpg
see fluid there...
but if head gasket is bad, then coolant is in the oil. For Sure.
ok.
happy kicking.