Original specifications are as follows:
|2 litre engines:
|2.4 litre engines:
||Champion N60Y or Bosch W300T 30
Looking at the following Champion specification table the code means the following:
||Thread size: 14mm, Reach: 3/4", Hex: 13/16"
||High performance heat range
||Standard projected core nose
The Champion N60Y plug is no longer available, but cross references to the NGK BP[heat rating]E[electrode type] where the heat rating can be from 6 to 10 and the electrode type S(standard) or T(triple). For example: NGK BP6ET or NGK BP10ES. You could also use the type with a resistor built in although this is not necessary.
For reference purposes I have reproduced the following information regarding the coding of NGK Spark plugs (the original article can be found at Z1-spark-plug-guide
The B8ES plug is 14mm thread (B), has a middle heat range (8), a thread length of 19mm (E), and a standard 'hook' style electrode (S).
The thread pitch is 1.25mm.
The platinum equivalent of the B8ES is B8EV.