Just to share my top overhaul costing here,
Done in Aug 2006.
Parts change / labour :-
1) Top gasket (complete set ) Ard RM350
2) Valve polishing rm5 / valve = Rm120
3) Skin head = Rm100
4) Labour RM550
Total = RM1120
Option :-
1) Thermostat Rm35 (Ori part)
2) Water pump ard Rm400 - Metal impeller (Ori Part)
3) Thermostat Housing - Metal type from chop shop Rm100
Total = Rm 535
I guess that all i changed, Hope i didn't miss out anything here.