The flame trap is very close kin to a pcv valve. Serves the purpose of venting crankcase gasses into the intake manifold. Yours, I believe, is cleverly hidden underneath the intake manifold, back between #3 and #4. The trap itself has a small end with a rubber hose pushed over it, and a big end that probably has the rubber hose held on with a wire tie. In later years they moved it up to the top of the manifold, where you can see it without a colonoscope, and reach it without three wrists per arm. A retrofit kit is available so that yours can be relocated.