Miscellaneous Codes
Engine Suffix Codes
The engine identification code consists of the engine assembly plant, the engine assembly date, and 3 letter suffix indicating the cubic inch displacement, the horsepower rating, and generally, what type of transmission was to be installed with the engine. Manual transmissions required a bushing in the rear of the bellhousing where an automatic transmission did not. Many engine "accessories" such as the carburetor, distributor, and exhaust manifolds were not installed at the engine assembly plant but rather at the final assembly plant.
|
Engine |
Transmission |
Notes |
||
|
Code |
Size-Carb |
HP-RPO |
||
| CKO | 402-4 | 375-L78 | Manual-4 | |
| CKP | 402-4 | 375-L78 (w/L89) | TH-400 | Aluminum Heads |
| CKQ | 402-4 | 375-L78 | Manual-3/4 | Heavy Duty Clutch |
| CKR | 402-4 | 330-LS3 | Manual-3/4 | |
| CKS | 402-4 | 330-LS3 | Manual-3/4 | Heavy Duty Clutch/LS3 |
| CKT | 402-4 | 375-L78 (w/L89) | Manual-3/4 | Aluminum Heads |
| CKU | 402-4 | 375-L78 (w/L89) | Manual-3/4 | Heavy Duty Clutch/Aluminum Heads |
| CTW | 402-4 | 350-L34 | TH-400 | |
| CTX | 402-4 | 350-L34 | Manual-3/4 | |
| CTY | 402-4 | 375-L78 | TH-400 | |
| CTZ | 402-4 | 350-L34 | Manual-3/4 | Heavy Duty Clutch |
| CZX * | 400-2 | 265-LF6 | Manual-4 | Monte Carlo |
| CRN * (2) | 454-4 | 360-LS5 | TH-400 | Monte Carlo |
| CRQ | 454-4 | 360-LS5 | TH-400 | |
| CRR | 454-4 | 450-LS6 | TH-400 | |
| CRS (1) | 454-4 | 450-LS6(w/L89) | TH-400 | Aluminum Heads |
| CRT | 454-4 | 360-LS5 | Manual M22 | |
| CRU | 454-4 | 360-LS5 | Manual M22 | Heavy Duty Clutch |
| CRV | 454-4 | 450-LS6 | Manual M22 | |
| CRX | 454-4 | 450-LS6 | Manual M22 | Heavy Duty Clutch |
| CRY (1) | 454-4 | 450-LS6(w/L89) | Manual M22 | Aluminum Heads/Heavy Duty Clutch |
Notes:
(1) There is some discussion about the 454 being sold with 454 engines and aluminum heads. One very respected source says that according to records at Tonawanda no 454 with aluminum heads. Their records indicate the L89 option was cancelled (not replaced) with the demise of the L78/L89 combination. On the other hand, some have reported seeing the CRS code on engine blocks and one registrant here has a dealer bill-of-sale plus the warranty protect-o-plate card both showing the CRY code.
(2) One source, Chevrolet by the numbers, shows CRN for a 1970 Monte Carlo 454/360 with TH400 where another source, Chevelle, Malibu & El Camino ID numbers 1964-87 shows the CRN code for a manual/4-speed. Every Chevelle LS5 build sheet I have shows RT for an LS5 w/manual transmission and RQ for an LS5 w/TH400. A Monte Carlo LS5 build sheet shows RN for an LS5 w/TH400. I'll take the information on a build sheet over other published data.
These figures are for the U.S. production of Chevelles only (unless
otherwise indicated) and does not include the Monte Carlo.
A total of 39,207 6-cyl engines were installed; 29,791 in U.S. built
Chevelles and 10,416 imported from Canada.
A total of 413,255 8-cyl engines were installed; 198,285 307cid, 150,745
350cid, and 64,225 402/454cid engines.
* Monte Carlo exclusive
CGR engine suffix has been noted on a Canadian-built LS3 Chevelle with
manual transmission.
How this 64,225 figure of combined 402/454 engines was arrived at is
not known. Given the number of Z25 and Z15 options (including optional
L78 and LS6 engines), the total arrived at is 63,372 for SS optioned
Chevelles but this total includes the two SS options both exported to
and imported from Canada so the exact U.S. figures are difficult to
ascertain.
GM of Canada documents indicate that 3,306 Z25 optioned Chevelle Sport
Coupes along with 299 Z15 (LS5 only) optioned Chevelle Sport Coupes
were exported for sale to the U.S.
In addition to these imports and exports, a total of 9,338 LS3 engines
must be accounted for somewhere in this 64,225 402/454 engine figure.
53,599 - Z25 SS 396 options ordered (51,455 base L34 plus 2,144 optional
RPO L78)
8,773 - Z15 SS 454 options ordered (4,298 base LS5 plus 4,475 optional RPO
LS6)
Chevrolet only reports 442,046 engines and transmissions on the Accumulative
Production Report of August 31, 1970. This number is only for U.S. built
Chevelles. There is no breakdown of engines or transmissions imported
from Canada.
The date and suffix code is always stamped on the engine pad as the above example show. The partial VIN stamping location seems to vary from plant to plant. Listed are locations reported for the various plants. If you have a partial VIN stamped in another location, please contact me with particulars and photos.
| Plant | Engine Pad | Oil Filter | Bellhousing Flange |
| Atlanta | Yes | ||
| Baltimore | Yes | Yes | |
| Flint | Yes | ||
| Kansas City | Yes | ||
| Van Nuys | Yes | Yes | Yes |
| Oshawa | Yes |
Engine pad, Arlington, TX.
Engine pad, Atlanta, GA.
Oil filter pad, Baltimore, MD.
Engine pad, Kansas City, MO.
Oil filter pad, Van Nuys, CA.
