Its the one for the rectangular cover just under the throttle body. Ive changed it before when I did all the intake gaskets but its leaking again. I would rather not buy an entire gasket kit but I cant for the life of me, remember what its called.

 

Youre having a hard time finding it because every place seems to call it something different. ZZP calls it an Intake End Cap Gasket.

Rockauto calls it a Bypass Gasket (under cooling system). For reference, fel pro #36021, mahle# C31274.

Looks like Delco calls it Engine Coolant Manifold gasket - pn should be 24505049, but double check before buying.

 

Thanks a ton.