1971 Chevelle Engine ID Codes - Engine Pad
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.
While there are the suffix codes associated with the LS6 engine, there is no evidence the LS6 was ever installed in a production 1971 Chevelle and the only LS6 options listed in the Accumulative Production Report of August 31, 1971 are 188 units for the 1971 Corvette.
|CLS||402-4||300-LS3||HD 3-speed (MC1)|
|CPP(1)||454-4||460-LS6||Manual-M22||There is no proof the LS6 was ever offered to the public in a 1971 Chevelle|
|CPR(1)||454-4||460-LS6||TH-400||There is no proof the LS6 was ever offered to the public in a 1971 Chevelle|
|CPY(2) *||454-4||425-LS6||TH-400||There is no proof the LS6 was ever offered to the public in a 1971 Chevelle or a 1971 Monte Carlo|
|CPZ(2) *||454-4||425-LS6||Manual-M22||There is no proof the LS6 was ever offered to the public in a 1971 Chevelle or a 1971 Monte Carlo|
(1) This code is found in the ENGINE SERIES NUMBER AND SUFFIX CHART of the Chevrolet Parts and Accessories Catalog dated August 1971 but does not differentiate between the Chevelle and the Monte Carlo; both are considered 13xxx series Chevelles. The CPP code is also found in Chevrolet by the numbers (1970-1975) by Alan Colvin but is listed at 425hp; the CPR code is not listed in this publication however. It should be noted that the ENGINE SERIES NUMBER AND SUFFIX CHART of the Chevrolet Parts and Accessories Catalog dated August 1971 has numerous engine code errors for 1964 to 1971.
(2) This code is found in Chevrolet by the numbers (1970-1975) by Alan Colvin and listed at 425hp and listed for Chevelle as well as Monte Carlo. It's also noted (under Chevelle) that only 10 of the CPY engines and 4 of the CPZ engines were built (although no such information is provided under Monte Carlo). These engine codes are also found on an old Chevelle decoder program and listed at 425hp. According to the First Generation Monte Carlo Club website, only a 355hp version of the 454 engine is listed for 1971 and it's believed this should be 365hp and not 355hp as no 355hp rated 454 engine can be found in another source. Chevrolet by the numbers (1970-1975) by Alan Colvin shows only the CPD coded 454/365hp for the 1971 Monte Carlo.
Engine production totals are listed for U.S. production only.
* Includes Monte Carlo (see note 2 above)
** Monte Carlo exclusive
A total of 24,617 6-cyl engines were reported installed in Chevelles.
However, this figure does not agree with the number of 6-cyl cars reportedly
built in the U.S. of 24,475. This is a difference of 142 6-cyl engines
without cars to put them in.
A total of 349,682 8-cyl engines were installed in Chevelles; 181,657 307cid, 152,390 350cid, and 15,635 402/454cid engines. However, again, this does not match the total of 8-cyl cars reportedly built in the U.S. of 344,288. This is a difference of 5,394 8-cyl engines without cars to put them in.
Engines reported for the (U.S.-built) Monte Carlo does match the production figure of 112,597 cars. Those break down to 102,192 350cid, 8,633 402cid and 1,772 454cid engines.
Chevrolet only reports 374,299 transmissions on the Accumulative Production Report of August 31, 1971. This number is only for U.S.-built Chevelles. This figure does not match the total reported U.S.-built Chevelles of 368,763. This is a difference of 5,536 transmissions (all types) without cars to put them in. The listed transmissions for the (U.S.-built) Monte Carlo does match the 112,597 engine and model production numbers.
Vintage Vehicle Services documentation of one Malibu sport coupe (13637) report shows 588 were built with Z15 option and 124 with LS3 and Z15 for U.S. sale (229 with LS5) and a second Malibu sport coupe (13637) report shows 319 were built with Z15 option and 124 with LS3 and Z15 for sale in Canada.
Vintage Vehicle Services documentation of one Chevelle sport coupe (13437) report shows 1,445 were built for sale in the U.S.; 541 with the YF3 "Heavy Chevy" option and 122 with M20 4-speed manual transmission.