Difference in AC R45TS Spark Plug Size
Can anyone explain why there is a size difference between vintage (4 green stripe) AC R45TS spark plugs (Measuring 75mm) versus vintage AC Igniter II R45TS spark plugs (Measuring 70mm)? Again both plug types are vintage NOS - 4 green stripe plugs. Any difference in using one size plug versus the other? I'm completing a restoration on a 1980 NCRS Top Flight car I've continuously owed since 81 and want to keep everything original equipment. I appreciate any information that can be shared. Thanks....