The story
The Firebird 400 used the GTO's 400 V8. In 1967 it was rated at 325 hp, with Ram Air as an option at the same rating but at higher rpm, by Pontiac's sheet.12
All 1967–68 400s had throttle restrictors that kept the carburetor's secondaries from opening fully, by Wikipedia's account.2one source
For 1968 the 400 made 330 hp, a new 400 H.O. 335 and the Ram Air 335, followed in March by the Ram Air II; in 1969 the Ram Air IV topped the list at 345 hp.2345
How to spot a Firebird 400
Dual-scoop hood
A hood with two scoops; with Ram Air they are open.6one source
«400» on the deck lid and hood
The figures «400» on the right of the deck lid and on the hood, by Over-Drive's account.678one source
Production by year
How many Firebird 400s were built each model year.
As a table, with notes
| Year | Built | Note |
|---|
| 1967 | no figure6one source | Pontiac counted six- and eight-cylinder cars with standard or deluxe trim, not models, by Over-Drive's account, so no source we have counts the Firebird 400s. |
| 1968 | no figure7one source | Pontiac counted six- and eight-cylinder cars with standard or deluxe trim, not models, by Over-Drive's account, so no source we have counts the Firebird 400s. |
| 1969 | no figure8one source | Pontiac counted six- and eight-cylinder cars with standard or deluxe trim, not models, by Over-Drive's account, so no source we have counts the Firebird 400s. |
Engines
Pontiac's option codes, from Wikipedia's engine table, which cites Sessler's Firebird Red Book. Over-Drive gives L30, L76, L74 and L67 for 1969; for the 400 it prints W-S6, not W66. «Std.» is the standard engine. Pontiac's AMA sheets name the engines by model, not by code.
| Years | Code | Engine | Rated |
|---|
| 1967 | W66 | 400 V8, 4-barrel | 325 hp12 |
| 1967 | L67 | 400 Ram Air V8, 4-barrel | 325 hp12 |
| 1968 | W66 | 400 V8, 4-barrel | 330 hp23 |
| 1968 | L74 | 400 H.O. V8, 4-barrel | 335 hp23 |
| 1968 | L67 | 400 Ram Air II V8, 4-barrel (from March) | 340 hp (open ruling)25 |
| 1969 | W66 | 400 V8, 4-barrel | 330 hp4one source |
| 1969 | L74 | 400 H.O. V8, 4-barrel (with Ram Air on the Trans Am) | 335 hp24 |
| 1969 | L67 | 400 Ram Air IV V8, 4-barrel | 345 hp24 |
Where the sources disagree
Every conflict behind the figures on this page. All rulings.
Open
The 1968 Ram Air II's rating
Our ruling: Unresolved. Wikipedia, citing Sessler's Firebird Red Book, and Over-Drive's engine list give the Ram Air II 340 hp; Consumer Guide gives 335, «25 below the comparable GTO unit», which would put the GTO's Ram Air II at 360 hp (our arithmetic); the GTO's own Ram Air II rating is an open ruling on the GTO pages. Pontiac's AMA sheet of August 1967 predates the engine and lists the Ram Air at 335 hp.
What each source says (2)
