I'm in the process of getting my brothers 2000 Poo running again after 4 years of sitting in the weeds. I am going to blast the exhaust and repaint it but when I took the auminum wraps off the pipe the insulation in there was caked on the pipe. I scraped it all off but am wondering what should I put there to replace it? I don't really want to buy new OEM insulation, is there any cheap substitute or just skip it?