18mm Alignment Dowels (Early) - For models built before September 30th, 2003. This kit includes a screw-in style stand pipe. These models will have the ICP Sensor on the HPOP cover.
18mm Alignment Dowels - For models built September 30th, 2003 - January 11th, 2006. The ICP sensor is located on passenger side valve cover above the glow plug control module.