hell....i ran 9's in the leading and the trailings capped off for over a year without noticing a difference using the "butt-dyno". I was under the impression that the trailings were there for mainly emmissions reasons?

 

My trailing coil blew up so no trailing spark, and I fried my leading plugs so I threw some FC trailing plugs in since that was all was available.



The difference between the plugs I was running ans the FC units is astounding. It feels like the timing is 10 degrees retarded, or possibly the air filter is made out of leather. Very poor power, and fuel economy dropped by over 30 percent.