compression of a stock 1968,383????,

If it`s the Magnum (old school ) version it would actually have a possitive deck height , around + .010 " . Watch the valve clearance when sellecting a cam. Get a set of 67' closed chamber heads with Felpro .043" head gaskets to get the comp way up . This however is not easy to live with on the street. (premium + booster all the time )
Have Fun !
Chryco 557 :wink: