For 1974, there were five models:
| The serial number system and locations were the same as the previous year with sixth symbol changed to a "4" to indicate 1974 model year. |
| Calais were numbered 6C4( )R4Q 100001 and up |
| DeVilles 6D5( )R4( ) 10D001 and up |
| Eldorados 6L()S4Q( ) 400001 and up |
| Broughams 6B69R4Q 100001 and up |
| Seventy-Five 6F()R4Q100001 to 350000 |
| Description | Standard Engine | Eldorado Engine | |
|---|---|---|---|
| Engine type | V-8 Overhead valves. Cast iron block | V-8 Overhead valves | |
| Main bearings | Five | Five | |
| Valve lifters | Hydraulic | Hydraulic | |
| Displacement | 472 cubic inches (7.7 litres) | 500 cubic inches (8.2 litres) | |
| Bore and stroke | 4.300 x 4.060 inches (109 x 103mm) | 4.300 x 4.304 (109 x 109.3 mm) | |
| Compression ratio | 8.25:1 | 8.25:1 | |
| Brake horsepower (net SAE) | 205 at 4400 rpm | 210 @ 3600 rpm | |
| Torque | 365 ft. lbs @ 2400 rpm | 380 ft. lbs. @ 2000 rpm | |
| Oil pressure | 35 psi | 35 psi | |
| Carburetor | Rochester four-barrel Quadrajet Model 4MV | ||
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