1970 Chevelle Build Sheet

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.

09/22/2009

09/21/2009

09/21/2009

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    

Arlington Partial VIN
Engine pad, Arlington, TX.

Atlanta Partial VIN
Engine pad, Atlanta, GA.

1970 Baltimore partial VIN
Oil filter pad, Baltimore, MD.

Kansas City Partial VIN
Engine pad, Kansas City, MO.

Van Nuys partial VIN
Oil filter pad, Van Nuys, CA.