Gasket Set Question

[TMurray845@domain.elided]

In the process of rebuilding my 77 Spider motor I can't figure out where this 
part of the gasket set goes.  It is a block of rubber @2" long with both 
shoulders cut down on one side.  I don't recall where I might have seen it 
while dismantling, but I know I've seen it somewhere.  It is not the sealing 
strips that go in the rear main.  Can anyone enlighten me.  My motor has 
Webers so it might be part of the spica system?  Anyway I don't want to get 
it all back in the car and have left out something that will cause serious 
failure.  Any help would be appreciated.

Thanks
Stan
Columbus, GA

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