Replaced my wires and boots this summer. If I remember correctly, it was 7mm wire and NGK boots.....TB05EM. Needed to take the coils off and 'root' around in the hole where the wire goes. Some wire was left in the when I pulled the wire out. Watch out for the spike in there that gets shoved into the copper wires. I ended up breaking mine and had to buy a whole NEW coil .ARRRRRRRRGGGGGG 3*&^%$#@. Did take a DREMMEL to get the majority of the old wire out.(Got that idea from another post) Once cleaned out, I glued the wires into the coil with a plastic/rubber epoxy. I also shortened up the wires. The ones I took out were approx 15 miles long............well mabey not quite that long......but they were way too long. Shortened them up enough to do away with the 'loom' but enough to let the engine 'flex'. Coil to sparkplug.....plus about 2-3 inches for engine movement. Definately made a difference over the OEM ones that have been in there since 1997. I'm a thinkin the resistor portion had increased in resistance and was holding the sleds potential back.