I remember reading somewhere that someone was using a different spark plug, that was longer than stock. This effectively put the electrodes closer to the 2.0 head plug position when using a 1.7/1.8 plug location.

Anyone know anything about that?

Seems dubious...

Mark - might be why I can't find it. Maybe I was dreaming. =D

...........AND if true....the spark plug would have threads exposed in the combustion chamber, which would promote detonation, and build carbon, and assist in ripping the threads out of the head upon removal.....exception....IF only the TIP/ ELECTRODE was PROTRACTED..longer....Never heard of a plug like that..so far.