CORVETTE ENGINE SERIES NUMBER AND SUFFIX CHART Cont 1965 396 8 CYLINDER Type Type Description Designation Description Designation Spec High Performance IF Note Engines are stamped with a source production date and type on serial pad 1966 327 8 CYLINDER Manual Trans HE Powerglide HO A I R HH Special High Performance HT A I R and Powerglide HR Power Steering HP Special High Performance and A I R HD Special High Performance C A C and A I R KH 427 8 CYLINDER Special High Performance Hyd Lifters IK Special High Performance IP High Performance IL Powerglide IQ A I R IM Powerglide and A l R IR Type Designations for some engines will be followed by an R Rochester or H Holly Carter to designate Carburetor requirements 1967 327 8 CYLINDER Manual Trans HE Powerglide HO A I R HH Special High Performance HT A I R and Powerglide HR Power Steering Special High Performance and C A C HP Special High Performance and A I R HD Special High Performance C A C and A R KH 427 8 CYLINDER 4 Speed or Powerglide IL A I R and Aluminum Heads JH Tri Carb JC Powerglide IQ Special High Performance and Tri Carb JE Powerglide and Tri Carb JD Heavy Duty IT A I R and Powerglide IR Aluminum Heads IU A l R Powerglide and Tri Carb JG A l R IM A l R Special High Performance and A I R and Tri Carb JF Tri Carb JA 1968 327 8 CYLINDER Manual Trans HE Hyd Steering and C A C HP 3Speed Automatic Trans HO Special High Performance HT 1974 GM PARTS DIVISION GENERAL MOTORS CORPORATION CHEVROLET P A 3OB 8