V9 CORVETTE ENGINE SERIES NUMBER AND SUFFIX CHART Cont 1968 427 8 CYLINDER Tvpe Type Description Designation Description Designation High Performance IL Special High Performance Tri Carb r IR High Performance and Tri Carb IM Heavy Duty IT High Performance Tri Carb and 3 Speed Special High Performance Tri Carb Automatic Trans IO and Aluminum Heads IU 3 Speed Automatic Trans IO 1969 350 8 CYLINDER High Performance HW Manual Trans HY High Performance C A C HX 3Speed Automatic Trans T H 400 HZ 427 8 CYLINDER High Performance 3Speed Tri Carb Special High Performance Automatic Trans T H 400 LL Heavy Duty Clutch LT High Performance LM Aluminum Heads Heavy Duty Clutch LU Tri Carb High Performance 3 Speed Heavy Duty 3 Speed Automatic Automatic Trans T H 400 LN Trans T H 400 LV Heavy Duty LO Aluminum Heads 3 Speed Automatic Aluminum Heads LP Trans T H 400 LW Tri Carb High Performance LO Tri Carb Special High Performance Tri Carb Special High Performance LR 3 Speed Automatic Trans T H 400 LX 1970 350 8 CYLINDER Manual Trans CTL High Performance Transistor Ignition C A C CTO 3 Speed Automatic T H 400 CTM Special High Performance CTR High Performance CTN Special High Performance Transistor Ignition CTU High Performance C A C CTO Special High Performance Transistor Ignition High Performance Transistor Ignition CTP 4 Speed CTV 454 8 CYLINDER High Performance 4 BBL 3 Speed 4 BBL Heavy Duty 3 Speed Automatic Automatic T H 400 CGW T H 400 CZN High Performance 4 BBL CZU High Performance 4 BBL Transistor 4 BBL Heavy Duty CZL Ingition CRI WAREHOUSING AND DISTRIBUTION DIVISION OF GENERAL MOTORS CORPORATION CHEVROLET I4 13