LS (LS2 / LS3 / LS6 / L92 ) Professional Flap Top: ( ... " and 4.065". Rings:1.2mm 1.5mm 3.0mm) LS (LS2 / LS3 / LS6 / L92 ) Professional Flap Top:( ... Rings:1.2mm 1.5mm 3.0mm)Flat Top,4.005''Bore, Rod lgth 6.125", Comp Ratio11.6: ... 1.115, -5cc Dome Vol, 4032 alloyFlat Top,4.005''Bore, Rod lgth 6.125", Comp Ratio10.6:1, ... Comp.Ht. 1.315, -5cc Dome Vol,4032 alloy LS (LS2 / LS3 / LS6 / L92 ) Forged Piston-Professional ...