Hi Frank
Yes we do offer the ported Plenums as well as ported stock throttle bodies.These units are hand ported,tb and blower case matched. The reason we do not extrude hone them is as follows. Although Extrude honing is a great process it is best for areas you cannot reach.As you push a media like extrude hone through a port it removes and or smooths what material is in it's path it however does not know what to remove or what to leave. Example: the plenum has a right hand bend in it moving from front to back and like a bend in the river the material is forced more to the outside then the inside which in many cases is where material needs to be removed.
The plenum cost is 200.00 on an exchange basis( no down time) and you can reach us at 954-917-9200
Paul