Spark Plug Wire's Burning out

Been having problems with spark wire's burning on the headers, I have tried a few differant ways including wire seperator, longer wire's, shorter wire's, zip tie's & differant boots & I have the same problem after 500 miles, they burn out on the headers.
Asked a few supplier's here in Oz about Mopar spark wire's with no luck.
Looking at high temp covers to solve the problem althorugh they look out of place, anyone have other surgestion?