They are heat barriers, about 1/4" thick that go in between the throttle body, and the intake manifold, or between the upper intake manifold, and the lower intake manifold "stacks". Also available for between the lower intake manifold "stacks", and the heads.
Outlaw Engineering makes them.
Do a search underphenolic spacers, and check my locker.
P.s. Thank you for our lockers, Chris!
http://www.subaru-svx.net/forum/show...enolic+spacers