The last 2 pics I posted are trick flow ads from trick flow, even on thier site they have the grooves ground into the lower intake..
Trick Flow® Track Heat® Intake Manifolds for Ford 5.0L: TFS-51500002 - trickflow.com
Trick Flow® Track Heat® Intake Manifolds for Ford 5.0L: TFS-515B0002 - trickflow.com
yea, but the grooves in the ad dont look like they were made by a drunk 5 year old.