MOTORDYNE BASIC 5/16 INCH PLENUM SPACER FX35 350Z G35 M35 MOTORDYNE BASIC 5/16 INCH PLENUM SPACER FX35 350Z G35 This stealth modification adds 11HP-13HP and is the simplest to install. The 5/16" plenum spacer outperforms the competition and is fully compatible with all stock and aftermarket strut bars. The engine cover easily fits and never needs to be cut. With t