My SSEi has a misfire on cylinder 4 and I am planning on replacing my spark plugs and wires today... and I have a few questions. I've been reading a little and it seems like the NGK TR55 V power plugs work really well in our vehicles. BUT... I plan on putting in a FWI, a free flowing cat, and dropping the SC pulley down to 3.5 inches in the near future. I was thinking a colder spark plug like the Autolite 104 would be better suited with these mods.
My question is would running the colder spark plugs now in my stock engine have any negative effects?? Could I put them in now? Or is the NGK'* the way to go?
98' Bonneville SSEi --- Large & Supercharged