Age is more of a factor than miles. Replace those things pronto, bud. The Belden wires from NAPA have a lifetime warrenty, and I haven't heard anything bad about them [yet to try them myself, since my engine is in pieces, and the plug wires are the least of my worries
]. Get some NGK TR60'*, and gap them at .60. I have original wires on my car, and I had over 2,000 ohms resistance on even the shortest wire. I do not even know how the hell they even worked. Just keep that in mind
. I have a 16 year old car, with 150k miles.. just in case you didn't know.