Lower Intake gasket pieces

The soild little gasket pieces are used to block or restrict the EGR passage from the heads to the intake manifold.
Do not install them on a street driven car if you want the EGR to work. The EGR shuts off at WOT (Wide Open Throttle), so it doesn't cause any HP loss.

The little pieces with the hole in them may mate up to an intake manifold with smaller EGR passages.