once na remove yung head you have to replace the gasket din. so better nga na save mo na and prepare for the worst case scenario. white smoke is an indication that your engine is possibly burning coolant, so kailangan mo rin ipa hydro-static test ang head, kung may warp you need din pa resurface. ang worst case kung may crack ay you will replace the head. while nandun ka na sa process you might as well consider replacing timing belt and water pump (depende sa engine)