Spark plug clamps

[Muddytazz]

I have something similar to this but made of alum instead of the tin one here pictured. The clamps are made of a nylon/delron/bakalite type of material. Over a period of time the heat breaks down the material and they fall apart. What I'm wanting to know is, with the insolation that is around the spark plug wire, is there any reason that I couldn't make my own clamps out of aluminum? Would I get any spark interferrence?
The black clamps are what I'm referring too.