Spark plug replacement

[badass98svt]

I shot a plug out of the head many many moons ago in my 4V. Scared the shit out of me.

 

[RAU03MACH]

I have never run into those problems
But I have seen it happen to others

 

[GTamas]

I noticed that one of my wires touched the headers and the rubber isolation got some cracks, but it's still holding together. Going to replace it.
It's a Taylor 8mm spiro-pro cable. Are there any drawbacks of just replacing 1 wire with the same brand/type, if the other wires are 15 years old, but in good shape? Or shall I go for a new set?

 

[RAU03MACH]

if there cracked and dry replace