If you are going to replace the ENTIRE wire and by that, I mean the wire and the resistor end(piece that connects to spark plug), you MIGHT want to change the rotor & the dist. cap as well.
Before you buy an ENTIRE wire set, look around at what's been said here(check archives). You can buy just the resistor tips and not the wire and tips. The wires are steel, unlike the cheap junk used on some of the newer cars. You'll save some $$$ changing just the resistor tips.
I had a slight miss on a 103 motor awhile back. I examined the dist. cap and rotor. I cleaned the rotor with some emory cloth as I've done on other makes of cars. My miss went away.
If you go thru the archives, you'll see many cases where wires/dist. cap/rotor have been changed and the car still ran less than expected.
You'll need to examine the dist. cap and rotor to really know if they need to be changed.