Ok I have given some thought on this. It seems that on the factory marks 'P' and with the crank keyway pointing up the timing is 180 degrees out ie exhaust just closed and inlet valve just about to open on induction stroke . So if I set it up per the book the timing will be out by the 180 which I assume will cause the problem of the Distributor needing to be 180 out (have seen this on a few engines) but apart from that nothing bad will happen (as the crank does not know what stroke the pistons are on)
So I plan to install the cam 180 out (as per book) so that the TDC will be on the compression stroke.
I have heard lots of people with Distributor problems ie wrong orientation and wonder if this could be part of the problem.
I can't believe this is a problem with all timing of a series cam but you might wonder.
I have just put the chain on to check and yes timing is 180 out according to marks. So either dodgy sprocket, or?????
Please feel free to comment as I can't believe this is a common issue.