Exhaust gasket part # or suitable alternative?

[ninefourteener]

Driver side..... not the manifold (header) gasket up against the exhaust ports..... but the FIRST o-ring gasket connecting the header to the very first pipe.

Any suitable alternatives?

Local Subie dealership has it on order for me.... but it won't be here till Monday.

Is it something I can pull out, and substitute with "something" at a local parts store, or will ONLY a Subie gasket work?

[ninefourteener]

Bump??? Anyone familiar with this particular gasket?