Mazda Miata 1.8 lts 85mm(+2)/ 4032/ Forged piston/Comp. height 30.5mm (STD)/ – 3.5cc /20mm pin Off Center/ Valve pocket depth Int.: 4mm (diam 36.5mm) Exh: 3mm (diam 31mm) /C.R.: 9:1..Use with Rings GNH 1mm, 1.2mm, 2.8mm.