I’ve see online discussions on occasion making a reference to a 1971-72 Pontiac 455 HO and calling it an LS5, resulting in someone posting a correction: “LS5 is a Chevrolet engine!” Well, sure, but Chevrolet didn’t own option codes. The truth is that brands within General Motors shared these UPC codes.
Take a look at UPC codes for transmissions like M20 and M40 and every GM brand allegiant will know what they are. Even options like air conditioning share the same C60 code across the board. Engines are no different, except when they are — context is everything!
Chevrolet’s LS5 was a 454 four-barrel introduced for 1970. It was rated at 360 horsepower for the Chevelle SS 454 and Monte Carlo SS 454, and 390 horses for big cars and the Corvette. With 1971 came lower compression and a different horsepower rating (now shared among all series). This engine would be available through 1972. However, Pontiac also used this code in 1971-72 for the 455 HO that was available on most A-bodies, and the Firebird Formula and Trans Am.
One of the most renowned Chevrolet engines is the L78, famous among fanatics because the solid-lifter 396 (rated at 425 horsepower in 1965, and 375 horsepower in 1966-1970) was capable of beating more substantial machinery despite being down on cubes. But here we are again with Pontiac messing with Chevy’s mojo, as the UPC code in the Pontiac world was used for the 400 four-barrel that was standard on GTOs from 1967-73. Though we know that as being rated at 350 horsepower, the L78 code generally pertained to engine size and carburetion, so both the 1969 Grand Prix and full-size pair of Catalina and Executive were available with L78 400 four-barrels, but altogether, they were three distinct engines for the three platforms. Even Oldsmobile was in on the act because the 350-horsepower Oldsmobile 4-4-2 was UPC L78 for 1966-67.
Another engine option code commonly seen was L75. As far as I know, it was first used in 1962 for the 300-horsepower 327 often seen in Corvettes, full-size cars, Chevelles, and Novas. It’s the same code used by Pontiac for the 1967-69 428 HO, then the (related) 455 HO for 1970. Would you believe Buick used the L75 code for both the 1969 400 Stage 1 as well as the ’70 455 Stage 1? Oldsmobile used L75 in 1964 for the Starfire 394, then used it in 1965-67 for the 425 Starfire V-8 installed in full-size cars. The UPC code would return in 1972 for the 455 four-barrel seen in Cutlasses (including those with the 4-4-2 package).
1966
If you’re starting to get mixed up, you’re not alone. Take a look at these pieces of Oldsmobile literature that use the same UPC codes for different-sized engines.
1967
In the end, context is everything.
