20-10-2020, 11:51 AM
I would also suggest that if you are proposing to 'pep up' an unknown standard engine, with a low comp head, keep to 18mm plugs. Many are the people who have fitted a late Ruby head to an unknown engine only to find that it runs as rough as a badgers bottom due to the 14mm plugs oiling up. Another reason to go with the Ricardo head, you can order it with the 18mm plugs and Dave will do it to a sensible compression ratio.