Try Smiths Engineering in Pennybridge Industrial estate, Ballymena. They bored out my engine, skimmed, ground out over size valves etc. Very good job and they're prices are very good compared to anywhere else. Loads of experience doing engines but be warned, may take a few weeks, they're always busy. Anythng else you need, send me a PM and i should be able to help.
Dave
I can't remember the damn name of the place, but we always got our heads skimmed in the place at Graham Garden's in Lisburn town centre. Was a long time ago now though, over 10 years