MotorDyne Plenum Spacers

[FndMspot]

Anyone have these plenum spacers installed, and have comments on increased sound and horsepower?

[infinitiandbeyond]

Personally, I am very tempted.

If I do it I'll also either get the lower manifold plenum upgrade OR take the factory one and send it off to have it extrude honed. Both if them look a little rough from being cast that the airflow could improve the performance of either.

http://www.extrudehone.com/pol....html

AAM also has a spacer:

http://www.alteredatmosphere.c...Z_ENG

As does SKUNK2:http://www.skunk2.com/engine-2.php?code=ENGPLN