Is their big difference between your 12mm and 25 mm manifold spacers alloytec ve

The 12mm and 25mm manifold insulators for the Alloytec (LY7) engine, increase torque by 10% and 13% respectively. If you tend to spend most of your time in the mid to top end range or low to mid range, then we would recommend the 12mm and 25mm manifold insulators respectively