depends really, if you not running to much boost you can get head set and bolts for about £30-40 from locql motor factors. you will need the head skimming as well that will cost between £30-40 and then you want to put it back together with a new belt £25 and give it o+f, plugs and air filter. just remember "cleanliness is next to godliness". make sure everyhting is clean and traces of old gaskets, sealants is removed before you put it back together.