MACE PLENUM SPACER AND MANIFOLD INSULATOR COMBO PACK TO SUIT HOLDEN CALAIS VE SIDI LLT 3.6L V6Installing either an insulator or a spacer on an engine such as the LLT definitely has its merits but to combine the two components, the gains are truly unrivaled when it comes to budget performance. By increasing the plenum chamber volume with the spacer and lengthening the intake runner length with the insulator, the volumetric efficiency of the motor is improved by a noticeable margin over the entire rev range. These parts are manufactured from a