C3 Corvette Engine Identification Codes
Last reviewed July 2026, maintained by Corvette-C3.com
topReading your engine's stamped ID pad
Every small block Corvette engine has a machined pad on the front of the block, just ahead of the passenger side cylinder head (often hidden behind the alternator). Big blocks carry the same information on a pad above the timing chain cover. Stamped into that pad is a partial VIN and a suffix code, a short string of letters that Chevrolet used on the assembly line to identify the engine's displacement, horsepower rating, and which transmission and options it was built to go with.
That suffix code is the quickest way to tell what engine you are actually looking at, since blocks were swapped, rebuilt, and mixed up over 50 years. The partial VIN portion is what buyers and appraisers check against the car's actual VIN to confirm a numbers-matching engine. The table below lists the suffix codes by year so you can decode what is stamped on your block.
1968 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| HE | 327 | Base | 300 | Rochester Q-jet & Manual Transmission |
| HO | 327 | Base | 300 | Rochester Q-jet & Turbo Hydra-Matic |
| HP | 327 | L79 | 350 | Rochester Q-jet, A/C, P/S & Manual Transmission |
| HT | 327 | L79 | 350 | Rochester Q-jet, Special Cam & 4-Speed |
| IL | 427 | L36 | 390 | Rochester Q-jet, Hydraulic Lifters & 4 Speed |
| IQ | 427 | L36 | 390 | Rochester Q-jet, Hydraulic Lifters & Turbo Hydra-Matic |
| IM | 427 | L68 | 400 | L36 Engine with Holley 3x2BC & 4-Speed |
| IO | 427 | L68 | 400 | L36 Engine with Holley 3x2BC & Turbo Hydra-Matic |
| IR | 427 | L71 | 435 | Holley 3x2BC, Mechanical Lifters & 4-Speed |
| IU | 427 | L89 | 435 | L71 Engine with Aluminum Heads & 4-Speed |
| IT | 427 | L88 | 430 | Holley 1x4BC, Heavy-Duty Engine & M22 4-Speed |
1969 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| HY | 350 | Base | 300 | Rochester Q-jet & Manual Transmission |
| HZ | 350 | Base | 300 | Rochester Q-jet & Turbo Hydra-Matic |
| HW | 350 | L46 | 350 | Rochester Q-jet, Special Cam & 4-Speed |
| HX | 350 | L46 | 350 | Rochester Q-jet, Special Cam, A/C & 4-Speed |
| GD | 350 | L46 | 350 | Rochester Q-jet, Special Cam, A/C, K66 & 4-Speed |
| LM | 427 | L36 | 390 | Rochester Q-jet, Hydraulic Lifters & 4-Speed |
| LL | 427 | L36 | 390 | Rochester Q-jet, Hydraulic Lifters & Turbo Hydra-Matic |
| LQ | 427 | L68 | 400 | L36 Engine with Holley 3x2BC & 4-Speed |
| LN | 427 | L68 | 400 | L36 Engine with Holley 3x2BC & Turbo Hydra-Matic |
| LO | 427 | L88 | 430 | Holley 1x4BC, Heavy-Duty Engine & M22 4-Speed |
| LV | 427 | L88 | 430 | Holley 1x4BC, Heavy-Duty Engine & Turbo Hydra-Matic |
| LR | 427 | L71 | 435 | Holley 3x2BC, Mechanical Lifters & 4-Speed |
| LX | 427 | L71 | 435 | Holley 3x2BC, Mechanical Lifters & Turbo Hydra-Matic |
| LP | 427 | L89 | 435 | L71 Engine with Aluminum Heads & 4-Speed |
| LW | 427 | L89 | 435 | L71 Engine with Aluminum Heads & Turbo Hydra-Matic |
| LT | 427 | L71 | 435 | Holley 3x2BC, Mechanical Lifters, MA6 & 4-Speed |
| LU | 427 | L89 | 435 | L71 Engine with Aluminum Heads, MA6 & 4-Speed |
| ME | 427 | ZL1 | 430 | ZL1 Performance Package (L88 Engine) & M22 4-Speed |
| MG | 427 | ZL1 | 430 | ZL1 Perf Package (L88 Engine) & M22 Turbo Hydra-Matic |
| MH | 427 | L36 | 390 | Rochester Q-jet, K66 & 4-Speed |
| MI | 427 | L36 | 390 | Rochester Q-jet, K66 & Turbo Hydra-Matic |
| MJ | 427 | L68 | 400 | L36 Engine with Holley 3x2BC, K66 & Turbo Hydra-Matic |
| MK | 427 | L68 | 400 | L36 Engine with Holley 3x2BC, K66 & 4-Speed |
| MS | 427 | Central Office Production Order, Details Unknown | ||
| MR | 427 | L88 | 430 | Holley 1x4BC, Heavy-Duty Engine & M22 4-Speed |
1970 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CTL | 350 | Base | 300 | Rochester Q-jet & 4-Speed |
| CTD | 350 | Base | 300 | Rochester Q-jet & 4-Speed |
| CTM | 350 | Base | 300 | Rochester Q-jet & Turbo Hydra-Matic |
| CTG | 350 | Base | 300 | Rochester Q-jet & Turbo Hydra-Matic |
| CTN | 350 | L46 | 350 | Rochester Q-jet, Performance Cam & 4-Speed |
| CTH | 350 | L46 | 350 | Rochester Q-jet, Performance Cam & 4-Speed |
| CTO | 350 | L46 | 350 | Rochester Q-jet, Performance Cam, A/C & 4-Speed |
| CTJ | 350 | L46 | 350 | Rochester Q-jet, Performance Cam, A/C & 4-Speed |
| CTP | 350 | L46 | 350 | Rochester Q-jet, Performance Cam, T/I & 4-Speed |
| CTQ | 350 | L46 | 350 | Rochester Q-jet, Performance Cam, A/C, T/I & 4-Speed |
| CTU | 350 | LT1 | 370 | Holley 1x4BC, Mechanical Lifters, T/I & 4-Speed |
| CTK | 350 | LT1 | 370 | Holley 1x4BC, Mechanical Lifters, T/I & 4-Speed |
| CTV | 350 | ZR1 | 370 | Performance Package (LT1 Engine) & M22 4-Speed |
| CZU | 454 | LS5 | 390 | Rochester Q-jet, Hydraulic Lifters & 4-Speed |
| CGW | 454 | LS5 | 390 | Rochester Q-jet, Hydraulic Lifters & Turbo Hydra-Matic |
| CRI | 454 | LS5 | 390 | Rochester Q-jet, Hydraulic Lifters, T/I & 4-Speed |
| CRJ | 454 | LS5 | 390 | Rochester Q-jet, Hydraulic Lifters, T/I & Turbo Hydra-Matic |
| CZL | 454 | LS7* | 465 | Holley 1x4BC, Mechanical Lifters, Aluminum Heads & 4-Speed |
| CZN | 454 | LS7* | 465 | Holley 1x4BC, Mechanical Lifters, Aluminum Heads & THM |
* Records indicate none were produced
1971 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CJL | 350 | Base | 270 | Rochester Q-jet & 4-Speed |
| CGT | 350 | Base | 270 | Rochester Q-jet & Turbo Hydra-Matic |
| CJK | 350 | Base | 270 | Rochester Q-jet & Turbo Hydra-Matic |
| CGZ | 350 | LT1 | 330 | Holley 1x4BC, Mechanical Lifters & 4-Speed |
| CGY | 350 | ZR1 | 330 | Performance Package (LT1 Engine) & M22 4-Speed |
| CPH | 454 | LS5 | 365 | Rochester Q-jet, Hydraulic Lifters & 4-Speed |
| CPJ | 454 | LS5 | 365 | Rochester Q-jet, Hydraulic Lifters & Turbo Hydra-Matic |
| CPW | 454 | LS6 | 425 | Holley 1x4BC, Mechanical Lifters, Aluminum Heads & 4-Speed |
| CPX | 454 | LS6 | 425 | Holley 1x4BC, Mechanical Lifters, Aluminum Heads & THM |
1972 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CKW | 350 | Base | 200 | Rochester Q-jet & 4-Speed |
| CDH | 350 | Base | 200 | Rochester Q-jet, NB2 & 4-Speed |
| CKX | 350 | Base | 200 | Rochester Q-jet & Turbo Hydra-Matic |
| CDJ | 350 | Base | 200 | Rochester Q-jet, NB2 & Turbo Hydra-Matic |
| CKY | 350 | LT1 | 255 | Holley 1x4BC, Mechanical Lifters & 4-Speed |
| CRT | 350 | LT1 | 255 | Holley 1x4BC, Mechanical Lifters, K19 & 4-Speed |
| CKZ | 350 | ZR1 | 255 | Performance Package (LT1 Engine) & M22 4-Speed |
| CPH | 454 | LS5 | 270 | Rochester Q-jet, Hydraulic Lifters & 4-Speed |
| CPJ | 454 | LS5 | 270 | Rochester Q-jet, Hydraulic Lifters & Turbo Hydra-Matic |
| CSR | 454 | LS5 | 270 | Rochester Q-jet, Hydraulic Lifters, K19 & 4-Speed |
| CSS | 454 | LS5 | 270 | Rochester Q-jet, Hydraulic Lifters, K19 & Turbo Hydra-Matic |
1973 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CKZ | 350 | L48 | 190 | 4-Speed |
| CLA | 350 | L48 | 190 | Turbo Hydra-Matic 400 |
| CLB | 350 | L48 | 190 | 4-Speed (California) |
| CLC | 350 | L48 | 190 | Turbo Hydra-Matic 400 (California) |
| CLD | 350 | L82 | 250 | Turbo Hydra-Matic 400 |
| CLH | 350 | L82 | 250 | Turbo Hydra-Matic 400 (California) |
| CLR | 350 | L82 | 250 | 4-Speed |
| CLS | 350 | L82 | 250 | 4-Speed (California) |
| CWM | 454 | LS4 | 275 | 4-Speed |
| CWR | 454 | LS4 | 275 | Turbo Hydra-Matic 400 |
| CWS | 454 | LS4 | 275 | Turbo Hydra-Matic 400 (California) |
| CWT | 454 | LS4 | 275 | 4-Speed (California) |
1974 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CKZ | 350 | L48 | 195 | 4-Speed |
| CLA | 350 | L48 | 195 | Turbo Hydra-Matic 400 |
| CLB | 350 | L48 | 195 | 4-Speed (California) |
| CLC | 350 | L48 | 195 | Turbo Hydra-Matic 400 (California) |
| CLD | 350 | L82 | 250 | Turbo Hydra-Matic 400 |
| CLH | 350 | L82 | 250 | Turbo Hydra-Matic 400 (California) |
| CLR | 350 | L82 | 250 | 4-Speed |
| CLS | 350 | L82 | 250 | 4-Speed (California) |
| CWM | 454 | LS4 | 270 | 4-Speed |
| CWR | 454 | LS4 | 270 | Turbo Hydra-Matic 400 |
| CWS | 454 | LS4 | 270 | Turbo Hydra-Matic 400 (California) |
| CWT | 454 | LS4 | 270 | 4-Speed (California) |
1975 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CHA | 350 | L48 | 165 | 4-Speed (Federal Emissions) |
| CHB | 350 | L48 | 165 | Turbo Hydra-Matic 400 (Federal Emissions) |
| CHC | 350 | L82 | 205 | 4-Speed (Federal Emissions) |
| CHR | 350 | L82 | 205 | Turbo Hydra-Matic 400 (Federal Emissions & California) |
| CHU | 350 | L48 | 165 | 4-Speed (Federal Emissions) |
| CHZ | 350 | L48 | 165 | Turbo Hydra-Matic 400 (California Emissions) |
| CKC | 350 | L82 | 205 | Turbo Hydra-Matic 400 (Federal Emissions) |
| CRJ | 350 | L48 | 165 | 4-Speed (Federal Emissions) |
| CRK | 350 | L48 | 165 | Turbo Hydra-Matic 400 (Federal) Emissions |
| CRL | 350 | L82 | 205 | 4-Speed (Federal Emissions) |
| CRM | 350 | L82 | 205 | Turbo Hydra-Matic 400 (Federal Emissions) |
| CUA | 350 | L48 | 165 | 4-Speed (Federal Emissions) |
| CUB | 350 | L48 | 165 | 4-Speed (Federal Emissions) |
| CUD | 350 | L82 | 205 | 4-Speed (Federal Emissions) |
| CUT | 350 | L82 | 205 | 4-Speed (Federal Emissions) |
1976 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CHC | 350 | L82 | 210 | 4-Speed (Federal Emissions) |
| CKC | 350 | L82 | 210 | Turbo Hydra-Matic 400 (Federal Emissions) |
| CKW | 350 | L48 | 180 | 4-Speed (Federal Emissions) |
| CKX | 350 | L48 | 180 | Turbo Hydra-Matic 350 (Federal Emissions) |
| CLM | 350 | Unverified | ||
| CLR | 350 | Unverified | ||
| CLS | 350 | L48 | 180 | Turbo Hydra-Matic 350 (California Emissions) |
1977 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CHD | 350 | L48 | 180 | Turbo Hydra-Matic 350 (California Emissions) |
| CKD | 350 | L48 | 180 | Turbo Hydra-Matic 350 (High Altitude) |
| CKZ | 350 | L48 | 180 | 4-Speed (Federal Emissions) |
| CLA | 350 | L48 | 180 | Turbo Hydra-Matic 350 (Federal Emissions) |
| CLB | 350 | L48 | 180 | Turbo Hydra-Matic 350 (High Altitude) |
| CLC | 350 | L48 | 180 | Turbo Hydra-Matic 350 (California Emissions) |
| CLD | 350 | L82 | 210 | 4-Speed (Federal Emissions) |
| CLF | 350 | L82 | 210 | Turbo Hydra-Matic 400 (California Emissions) |
1978 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| CHW | 350 | L48 | 185 | 4-Speed (Federal Emissions) |
| CLM | 350 | L48 | 185 | Turbo Hydra-Matic 350 (Federal Emissions) |
| CLR | 350 | L48 | 175 | Turbo Hydra-Matic 350 (California Emissions) |
| CLS | 350 | L48 | 175 | Turbo Hydra-Matic 350 (High Altitude) |
| CMR | 350 | L82 | 220 | 4-Speed (Federal Emissions) |
| CMS | 350 | L82 | 220 | Turbo Hydra-Matic 350 (Federal Emissions) |
| CUT | 350 | L48 | 185 | Turbo Hydra-Matic 350 (Federal Emissions) |
1979 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| ZAA | 350 | L48 | 195 | 4-Speed (Federal Emissions - Early) |
| ZAB | 350 | L48 | 195 | Turbo Hydra-Matic 350 (Federal Emissions - Early) |
| ZAC | 350 | L48 | 195 | Turbo Hydra-Matic 350 (California Emissions - Early) |
| ZAD | 350 | L48 | 195 | Turbo Hydra-Matic 350 (High Altitude) |
| ZAF | 350 | L48 | 195 | 4-Speed (Federal Emissions) |
| ZAH | 350 | L48 | 195 | Turbo Hydra-Matic 350 (Federal Emissions) |
| ZAJ | 350 | L48 | 295 | Turbo Hydra-Matic 350 (California Emissions) |
| ZBA | 350 | L82 | 225 | 4-Speed (Federal Emissions) |
| ZBB | 350 | L82 | 225 | Turbo Hydra-Matic 350 (Federal Emissions) |
1980 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| ZAK | 350 | L48 | 190 | Turbo Hydra-Matic 350 (Federal Emissions) |
| ZAM | 350 | L48 | 190 | 4-Speed (Federal Emissions) |
| ZBC | 350 | L82 | 230 | Turbo Hydra-Matic 350 (Federal Emissions) |
| ZBD | 350 | L82 | 230 | 4-Speed (Federal Emissions) |
| ZCA | 305 | LG4 | 180 | Turbo Hydra-Matic 350 (California Emissions) |
1981 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| ZDA | 350 | L81 | 190 | 4-Speed (Federal Emissions) |
| ZDB | 350 | L81 | 190 | Turbo Hydra-Matic 350 (California Emissions) |
| ZDC | 350 | L81 | 190 | 4-Speed (California Emissions) |
| ZDD | 350 | L81 | 190 | Turbo Hydra-Matic 350 (Federal Emissions) |
1982 Corvette Engine Identification Codes
| Engine Code | Cubic Inches | Order Code | HP | Applicable Equipment |
|---|---|---|---|---|
| ZBA | 350 | L83 | 200 | Turbo Hydra-Matic 700-R4 (Federal Emissions) |
| ZBC | 350 | L83 | 200 | Turbo Hydra-Matic 700-R4 (California Emissions - Early) |
| ZBN | 350 | L83 | 200 | Turbo Hydra-Matic 700-R4 (California Emissions) |