x2 /Schmitt . Sealed Power/TRW has a forged piston, which I used, and it is for 1968,383 Magnum . I'm not sure but I think 1969 383 Magnum piston is the same part . 1970 is a little lower in c.r. but the gram weights are the same . This piston is legal for NHRA stock Eliminator . However I used this piston with a "915" head @ 78.5 cc with a factory head gasket @ .022" thickness gives me a pump gas friendly 9.6: 1 c.r.. The closed chamber heads provide a quench area to help combat detonation . This won't get me in the low 12's . Eddy heads and intake might just do it , though . Later, Tom
