Phonolic Gasket's

[yellow-dc2]

This was an interesting read
http://www.skylinesaustralia.com/forums/index.php?showtopic=168016&st=0&gopid=3148632&#entry3148632

[bennjamin]

already covered , and being sold in the traders place.
Hondata and copy brands make a plastic gasket to suit some hondas - and it does decrease the intake manifold temp and thus "intake charge" temp.
No difference on a road car but on something tuned or on a track work out it would make a difference