COMP Cams Camshaft Cv6B 260HR-104WD and Light Towing Has Smooth Idle Works with Stock Components. Adjustable Valve Train Required For Carbureted Applications Balance shaft equipped 4. 3L engines were introduced in '92 but GM continued to produce the previous version until '94. Non balance shaft 4. 3L's (' 85 '94) shared their timing cover with the small block Chevy V8 engine. The balance shaft 4. 3L's timing cover is noticeably taller than the non balance shaft version. Catalog User