Intake manifold gasket

I recently had to change the head gaskets on my 71'. 1987 Buick 231 V6. I am now ready to re-install the intake manifold. The intake kit comes with an O-ring but for the life of me I can't figure out where it is supposed to go. It is the gasket with the metal valley, I am trying to attach a pic from photobucket but having troubles for some reason.

Any ideas?

Thanks

Link to Summit

http://www.summitracing.com/parts/fel-ms96037

 

Distributor o ring. ?

 

That was my first thought. Good news is I did not have to remove the distributor to get the intake off.