Rare indeed! Chevrolet ran out of Muncie 4-speeds in '74, Pontiacs were already using the Warner ST-10. The last 454 4-speed to roll off the line in Oshawa was in April 1974. In Oshawa they built 18 base Malibu coupes with the LS4 M21 combo, another 65 Laguna Type S-3 with the 454 M21. Not all of those were destined for Canada, some were intended for U.S. sale. I don't know how many Malibu Classics had that drivetrain. The El Camino was U.S. built. I seem to recall a grand total of about 942 of the 1974 Chevelle / El Camino production had the M21 Muncie for 1974 (U.S. figure or combined Canada / U.S. I am not sure). The M21 was only available with the 454 on coupes (any series) or El Caminos (ditto).

Horsepower was a low 235 net, but that is due to lean carb mixture, EGR, A.I.R. pump, lazy timing curve compounded by TCS that locked out vacuum advance until top gear was held continuously for 30 seconds (who says VW was the only emission-rigging corporation - they ALL did it). It still had 360 NET lbs/ft of torque despite the poor factory tuning (for emissions purposes). It would be easy to retune for better performance and economy. Stock they were good for 10 mpg Imperial (8 U.S.) all the time. For 235 NET horses it certainly will feel a lot stronger than that low number suggests. The El Camino in the ad has considerably more power than stock.

Orange was not a factory colour for Chevelles in '74 but they did have a Bronze that was sort of orangey.

The LS4 came with a thermostatic fan and HEI as standard in 1974.

Transmission will be an excellent fine-spline Muncie M21, but it won't be a rock crusher M-22 (they stopped after '72). Factory axle ratio was 3.42:1. The 454 required power steering & brakes & a h.d. battery.