I use a product called "High Tack" made by Permatex AKA 3M or Loctite. The red colored spray is a Hylomar type non-hardening sealer that soaks into the gasket and helps hold the gasket in place while you place the manifold, it is fantastic stuff and when it comes time to disassemble it will make things easier to boot. Problem solving this way has never been easier.
“She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself.”
— Han Solo