My car over heated I waited for it to cool down.

You are now in a bit of a bind, the engine should have been set at TDC before removing the timing belt, these are interference engines and moving the crank with no belt will bend valves, about the only thing to do is remove the spark plugs and VERY carefully move the cam a little and then move the crank a little until you eventually reach TDC if anything starts to bind up BACK OFF this is very delicate and to much pressure will bend a valve, if in doubt tow to your Holden dealer and get them to do it, it will be cheaper than having to pull the head and fix it if you get it wrong.