"porting" the stock upper box to match SLP runners is easy.
lay the gasket on the plenum, run the bolts part way in to hold it the way it will be lined up when installed, hold the gaskets flat against the plenum and trace the openings with a marker. then jsut go back with a dremel tool/die grinder and make the openings in the plenum the same size as the ones in teh gaskets.
you can also do the same to the runners to makesure there are no casting flaws obstructing air flow.
right behind the throttle body, inside the plenum, you will find a casting ridge that also shoudl be ground down.
it only takes a few hours and the money you save not paying someone can go towards other mods
