Hi guys when u bore a motor does anything have to be done to the head,bigger valves ect.

Not if it is a standard .5mm or 1.0mm rebore but if it is a big bore you will have to check combustion chamber clearance around the edges depending on what chambers the engine uses not everything is as it left the factory some 40 odd years later in some cases.

Whenever you fix the bottom end make sure valves, Guides and seals are good or it will draw oil past the guides and smoke when you back off as the increased vacuum from a fresh bottom end will find problems that did not exist with low compression and worn bores.