P.A.I. C-15 high performance in-frame kit. This kit fits the 6NZ serial number. 18:1 piston. Ceramic coated pistons, rings and bearings! OEM Cat Liners! Benefits from the high performance kits are... 3 year unlimited mile warranty Coated Pistons, Bearings and Rings 7 Layer HP Head Gasket Temperature Stability Better Fuel Economy Longer Life *Free Shipping!! [gravityform id="22" title="true"]