I need to install new packing in my stock muffler. I'm a little unsure what packing I should be buying. I'm looking at the FMF premier packing or just the cheap FMF packing they also sell. Which one do I want and if I just got the cheap packing, do I need to reuse the inner packing (looks like steel wool) that I removed? Is there something else I should be looking instead of the FMF products?