Thanks for all the help,from the pictures that Steve sent me, it appears all the cam lobes are facing down which makes sense as all the valves should be closed. The cam chain job is fairly straightforward however you need to remove the clutch basket, taking the head off is straightforward removing valves etc, with my head it was cracked from the plug under the exhaust valve seat and down the port for about an inch,had it welded up by a firm in Shropshire Motorcast they appear to have done a good job and reasonably priced, hope this helps.
Regards Rod