Just read this ...Abit late I know ..Overheating ...blocked /gunged up water jacket in block?/Timing too far advanced?/Radiator may look ok ,but has it got blocked tubes?/Thermostat not opening correctly to maximum(even new ones can do this!)/correct head gasket fitted ,not blocking water holes from head to block?/water pump internal vanes slipping on shaft inside the pump?/correct diam. pulley on w/pump ,therefore pump running at correct speed?Cant think of anymore at the moment!