I have two 1976 Detroit Diesels in my boat and have to have seals done from time to time as some of the new ones are sold out. I had to make exhaust manifold gaskets twice for exhaust risers that can withstand 700F operating temperatures. This 5961 material is the best I have found for such a gasket. Using a simple band saw and bench drill I got the job done. The material holds up well for cutting and drilling, much better than others I've tried. It will never be an easy and quick job, but with