1972 Chevelle Protect-O-Plate Decoding Engine

ENGINE IDENTIFICATION

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.

K = McKinnon Industries assembly plant
0818 - August 18
CKD = 350/175 L48 w/TH350

Engine Assembly Plant - 1st letter
Code	Assembly Plant
F or V	Flint, Michigan
T	Tonawanda Engine Plant
*K	McKinnon Industries, ON

Assembly Month - 1st and 2nd numbers
Number	Month	Number	Month
01	January	02	February
03	March	04	April
05	May	06	June
07	July	*08	August
09	September	15	October
11	November	12	December

Assembly Day - 3rd and 4th numbers
01...31

Engine			Transmission	Notes
Code	Size	HP
CAH	250-1	110	Manual-3	Low Compression Engine
CBA	250-1		Manual-3/4	A.I.R./Smog CAM (Calif), NB2
CBD	250-1		Manual-3	A.I.R./Smog CAM (Calif), taxi NB2
CBG	250-1	110	Manual-3
CBJ	250-1	110	Powerglide
CBK	250-1	110	Powerglide	Taxi
CDL	250-1	110	Powerglide	A.I.R.
CDM	250-1	110	Standard	A.I.R.
CSD	250-1		Powerglide	A.I.R./Smog CAM (Calif), NB2
307 ↓
CAY	307-2		Manual-3/4	A.I.R./Smog CAM (Calif), NB2
CAZ	307-2		Powerglide	A.I.R./Smog CAM (Calif), NB2
CKG	307-2	130	Standard
CKH	307-2	130	Powerglide
CMA	307-2		TH-350	A.I.R./Smog CAM (Calif), NB2
CTK	307-2	130	TH-350
350 ↓
CAR	350-2	165-L65	TH-350	A.I.R./Smog CAM (Calif), Police NB2
CDA	350-2	165-L65	Manual-3/4	A.I.R./Smog CAM (Calif), NB2
CDD	350-4	175-L48	TH-350	A.I.R./Smog CAM (Calif), NB2
CDG	350-2	165-L65	Manual-3/4	A.I.R./Smog CAM (Calif), NB2
CKA	350-2	165-L65	Manual-3/4
CKB	350-2	165-L65	TH-350
*CKD	350-4	175-L48	TH-350
CKK	350-4	175-L48	Manual-4
CMD	350-2	165-L65	TH-350	A.I.R./Smog CAM (Calif), NB2
CSH	350-2	165-L65	TH-350	Police
CTL	350-2	165-L65	TH-350
402 ↓
CLA ⁽¹⁾	402-4	240-LS3	Manual-4
CLB ⁽¹⁾	402-4	240-LS3	TH-400
CLS	402-4	240-LS3	Manual-3
CTA	402-4	240-LS3	Manual-3/4	A.I.R./Police - Taxi
CTB	402-4	240-LS3	TH-400	A.I.R.
CTJ	402-4	240-LS3	TH-400	A.I.R./Police - Taxi
454 ↓
CPA	454-4	270-LS5	Manual-3/4
CPD	454-4	270-LS5	TH-400
CRW	454-4	270-LS5	TH-400	A.I.R.
CRX	454-4	270-LS5	Manual-3/4	A.I.R.

⁽¹⁾ CLA, CLB, and CLS engine codes are shown in numerous publications but there is an ongoing debate if a 402 engine without A.I.R. was ever installed in a 1972 Chevelle, regardless of final assembly plant. If anyone has documented proof such as a build sheet or warranty Protect-O-Plate card showing either CLA, CLB, or CLS engine codes, please contact me via the Contact page.