And to add, oil pump was given the all clear by engine reconditioner who did the honing, and i checked all clearances were in spec during rebuild.

BTW, if anyone has any AFR equipment in the Preston/Blackpool/North West areas then i'll gladly cross your palm with some beer tokens to get it checked out.

I spent more than i budgeted rebuilding the engine so if i can work the niggles out myself it saves the time and expense of taking it to 'an expert'.