1970 Chevelle SS Engine Codes and Production Numbers

Engine Code         Cu. In. & RPO                                                 Transmission

CKO                           402-4 375-L78                                            4 speed manual

CKP                           402-4 375-L78 (w/L89)                                TH-400

CKQ                           402-4 375-L78                                            Manual-3/4 HD Clutch

CKT                           402-4 375-L78 (w/L89)                                Manual-3/4 speed

CKU                           402-4 375-L78 (w/L89)                                Manual-3/4 HD Clutch

CTW                          402-4 350-L34                                            TH-400

CTX                           402-4 350-L34                                            Manual-3/4 speed

CTY                           402-4 375-L78                                            TH-400

CTZ                           402-4 350-L34                                            Manual-3/4 speed HD Clutch

CRQ                           454-4 360-LS5                                           TH-400

CRR                           454-4 450-LS6                                           TH-400

CRS (1)                      454-4 450-LS6(w/L89)                                TH-400

CRT                           454-4 360-LS5                                           4 speed manual M22

CRU                           454-4 360-LS5                                           4 speed manual M22 Heavy Duty Clutch

CRV                           454-4 450-LS6                                           4 speed manual M22

CRX                           454-4 450-LS6                                           4 speed manual M22/HD Clutch

CRY (1)                      454-4 450-LS6(w/L89)                               4 speed M22/HD Clutch

Notes:

L89 – designates Aluminum Head Option

(1) In 1970 there is a dispute as to whether any 454 LS6s where equipped with aluminum heads. A respected source contends that no 454 were built with aluminum heads according Tonawanda records. According to said source, Tonawanda records indicate the L89 (aluminum head) option was cancelled and not replaced at the end of L78 production in November of 1969.

However, some have reported that the CRS (aluminum head) code has appeared on engine blocks. It is also reported that one individual has a warranty protect-o-plate card showing the CRY code.

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.

GM of Canada documents establish that 3,306 Z25 (SS396) and 299 Z15 (SS454 – LS5 only) optioned Chevelle Sport Coupes were exported for sale to the U.S.

Total 1970 Chevelle SuperSport Production numbers:

53,599 – Z25 SS396 options ordered (51,455 base L34 plus 2,144 optional RPO L78)
8,773 – Z15 SS454 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.