1973 Firebird Engine Options
| RPO Code | UPC Code | Type | Source | Displ cid | Bore & Stroke | Carb | Comp | HP/RPM Net | Torque/RPM | VIN | Engine Block code(s) | Trans RPO | UPC | Transmission | Axle | Opt Axle | Base | Esprit | Formula | Trans Am | Notes |
| 35D | L20 | Inline 6 | Chevrolet | 250 | 3.875 x 3.531 | 1 bbl | 8.5:1 | 110@3800 | 185@1600 | D | CCC, CCD | 36B | M12 | 3 Speed Manual (Floor Shift) | 3.08 | | S | n/a | n/a | n/a | Not available with Air Conditioning. |
| CCA, CCB | 36L | M38 | 3-Speed Turbo Hydramatic Transmission (Turbo 350) | A | n/a | n/a | n/a |
| 35M | L30 | V-8 | Pontiac | 350 with single exhaust (Esprit) | 3.875 x 3.75 | 2 bbl | 7.6:1 | 150@4000 | 270@2000 | M | XR | 36B | M12 | 3 Speed Manual Floor Siift | 3.08 | 3.42 | A | S | S | n/a | |
| 175@4400 | 280@2400 | N | 36E | M20 | 4 Speed Wide Ratio Manual Transmission (Floor Shift) | n/a | n/a | A | n/a |
| YL, YR, ZR, ZT | 36L | M38 | 3-Speed Turbo Hydramatic Transmission (Turbo 350) | 2.73 | 3.08 | A | A | A | n/a |
| 35R | L65 | V-8 | Pontiac | 400 with single exhaust | 4.125 x 3.75 | 2 bbl | 8.0:1 | 170@3600 | 320@2000 | R | YX, YZ, ZK, ZX | 36L | M40 | 3-Speed Turbo Hydramatic Transmission (Turbo 400) | 3.73 | 3.08 | n/a | A | n/a | n/a | |
| 35S | L78 | V-8 | Pontiac | 400 | 4.125 x 3.75 | 4 bbl | 8.0:1 | 230@4000 | 325@3200 | T | WS, Y6, YG | 36E | M20 | 4 Speed Wide Ratio Manual Transmission (Floor Shift) | 3.42 | | n/a | n/a | A | n/a | |
| WK, WP | 36H | M21 | 4 Speed Close Ratio Manual (Floor Shift) | n/a | n/a | A | n/a |
| Y3, YS, YT, XN | 36L | M40 | 3-Speed Turbo Hydramatic Transmission (Turbo 400) | 3.08 | 3.42 | n/a | n/a | A | n/a |
| 35W | L75 | V-8 | Pontiac | 455 | 4.15 x 4.21 | 4 bbl | 8.0:1 | 250@4000 | 370@2800 | Y | WT, WW | 36H | M21 | 4 Speed Close Ratio Manual (Floor Shift) | 3.08 | 3.42 | n/a | n/a | A | S | |
| YA, YC, YD, YK, X7. XM, XE, XL | 36L | M40 | 3-Speed Turbo Hydramatic Transmission (Turbo 400) | n/a | n/a | A | A |
| 35X | LS2 | V-8 | Pontiac | 455 Super Duty | 4.15 x 4.21 | 4 bbl | 8.0:1 | 310@4000 | 390@3600 | X | W8, ZJ | 36E | M20 | 4 Speed Wide Ratio Manual Transmission (Floor Shift) | 3.42 | | n/a | n/a | A | A | |
| Y8 | 36L | M40 | 3-Speed Turbo Hydramatic Transmission (Turbo 400) | n/a | n/a | A | A |
1973 Firebird Transmissions
| RPO Code | UPC Code | Type | Usage | Codes | Base | Esprit | Formula | Trans Am | Notes |
| 36B | M12 | 3 Speed Manual Transmission, Floor Mounted | L22 250 cid Inline 6 Cylinder | | S | n/a | n/a | n/a | |
| L30 350 cid V8 Floor Shift | A | S | S | n/a |
| 36E | M20 | 4 Speed Wide Ratio Manual Transmission (Floor Shift) | L30 350 cid V8 | | A | A | A | n/a | Standard on Trans Am with LS2 Super Duty |
| L78 400 cid V8 4bbl | n/a | n/a | A | n/a |
| LS2 Super Duty 455 | n/a | n/a | A | A |
| 36H | M21 | 4 Speed Close Ratio Manual (Floor Shift) | L78 400 cid V8 4bbl | | n/a | n/a | A | n/a | |
| L75 455 cid V8 4bbl | n/a | n/a | A | S |
| 36L | M38 | 3-Speed Turbo Hydramatic Transmission (Turbo 350) | L22 250 cid Inline 6 Cylinder | | A | n/a | n/a | n/a | |
| L30 350 cid V8 | A | A | A | n/a |
| 36L | M40 | 3-Speed Turbo Hydramatic Transmission (Turbo 400) | L65 400 cid V8 2bbl | | n/a | A | n/a | n/a | |
| L78 400 cid V8 4bbl | n/a | n/a | A | n/a |
| L75 455 cid V8 4bbl | n/a | n/a | A | A |
| LS2 Super Duty 455 | n/a | n/a | A | A |
1973 Engines
Where to find the Engine ID stamping
Chevrolet made Inline 6 Cylinder Engine (Typical)
Pontiac V-8 Engine (Typical)
The Pontiac Super Duty 455 Engine
Examples shown on this page consist of scanned images or reproduction artwork that can not be faithfully reproduced on a computer screen. Illustrations are for example only. Consult with your vendors offerring reproduction
parts for their historical accuracy.