Witch's Spark plugs

I try to understand what brands of spark plugs I can put on the mk2 1967. 3.4 … in the manual it says Champio N12Y … compression 7: 1 … but I have only found compression 8: 1 … compression really matters to select the ones plugs…

Here is a listing of plugs to replace the N12Y. Paul.

I have used NGK BP6ES, with great success.