The El Camino
I am often asked, "Is my El Camino a Malibu?" Well, that depends.
Your El Camino is definitely a Chevelle series (13xxx), just a different body style than a sedan, sport coupe, sport sedan, convertible, or station wagon. The El Camino came in two different series, the base 134/13580 and 135/13680 series. In the case of the 1964 model year, the series were 53/5480 and 55/5680 and 1968 with the one-year only El Camino SS396, the 13880 series. So, one would need to look at the series to see if their El Camino is a base series, Malibu series, or SS396 series.
Beginning in 1972 the GM VIN schema changed to a single letter to denote the series but the Fisher Body trim tag style number remained the same until the 1973 model year. The letter "C" was used for the base, Chevelle, series and the letter "D" was used for the Malibu series. So a base 1972 El Camino would be 1C80 where a Malibu series El Camino would be 1D80.
Another question often asked, "Is my El Camino a Chevelle?" Yes, just a different body style as noted above.
To address the Malibu question, different years have different methods (aside from the VIN or trim tag style number) to denote a Malibu series. Here are photos of emblems or script for each model year showing the El Camino is, indeed, a Chevelle.
Trim above glove box door identifies this as an El Camino while script on the front fenders identify this as a Chevelle. This car happens to be a 55/5680 Malibu series El Camino.
There is no El Camino trim above the glove box on this 53/5480 300 series El Camino and the Chevelle script is clearly shown on the front fenders. Also note the Chevrolet nameplate on the dash. The Chevrolet nameplate was present on all 1964 Chevelles unless air conditioning was ordered in which case the nameplate gave way to the dash mounted air conditioning vent.
1964 was the only model year to have Chevelle script or nameplate on the car.
For 1965 the Chevelle script was removed from the front fenders but Malibu (for the 135/15680) series remained on the trim above the glove box.
When air conditioning was not ordered, the Chevrolet nameplate remained on the dash above the radio hole but gave way to the dash vent when air conditioning was ordered.
1966 showed no Chevelle script or emblems but the Malibu series 135/15680 shows Malibu on the bezel above the glove compartment where the 300 Deluxe series 133/13480 does not.
1967 continued the theme of no Chevelle script or badging but the 135/13680 Malibu series has Malibu on bezel above the glove box where the 300 Deluxe series 133/13480 has no such trim.
Both the 1967 300 Deluxe and Malibu series El Camino also got a Chevelle horn button.
The 1968 model year was the only year the SS396 El Camino received its own series, 13880. Note additional side trim, blacked-out grille with SS396 emblem and, in this El Camino's case, optional D96 stipe.
Compare the base 300 Deluxe series, 133/13480 in the top photo (white El Camino) to the Malibu series, 135/13680 in the center photo (red El Camino). Note the Malibu script on the fenders.
The Malibu series El Camino also received a Malibu emblem on the door panels (as well as the emblem above the glove box) where the 300 Deluxe was void of any emblems and the SS396 series got its own SS396 emblems.
Various steering wheels were used depending on the model and options but the Malibu series and SS396 series were noted on the steering wheel as well as the bezel above the glove box. See here for more.
For 1969 the Malibu fender script disappeared from the 135/13680 Malibu series El Camino.
The 133/13480 300 Deluxe series El Camino steering wheel shows a bowtie emblem and no emblems above the glove box. The Malibu series steering wheel has a Malibu emblem as well as the bezel above the glove box and Malibu nameplate on the door panels. The SS396 (RPO Z25) optioned Malibu series El Camino received a steering wheel with an SS nameplate as well as an SS396 bezel above the glove box and SS396 door nameplates.
The 1970 model year pretty much continued the them of 1969.
The same style steering wheel with bowtie emblem and lack of trim above the glove box identifies the 133/13480 300 Deluxe series El Camino.
The 135/13680 Malibu series got a Malibu nameplate on the steering wheel but gone were any nameplates above the glove box and door panels due to the vent pane regulator handle. The SS396/SS454-optioned Malibu El Caminos followed suit with the only difference being a steering wheel with an SS emblem on it. See here for more.
1971 saw the demise of even the Malibu script on the steering wheel, now replaced with just Chevrolet. Only the Z15 SS-optioned El Camino got a new SS emblem on the steering wheel. See here for more.
1972 followed suit with 1971. See here for more.