1967 ~ Barracuda 383-S and Dart GTS-383 ~ 280 HP 'How can this be.'

Fudging the Horsepower Numbers for 1967

Chevrolet >
Re-factored the 1966 'L-79' 327/350 HP to {325 HP} for 1967
in the Chevy 'II' Nova SS cars.

This dropped the Weight-to-Horsepower factor from {8.58 Wt/HP} to a
now {9.23 Wt/HP}

The 'new' HP Factor permitted the 1967 Chevy 'II' 327/325 HP cars to
run in A/Stock {8.70 to 9.49 Wt/HP} for 1967.

The 1966 Chevy 'II' 327/350 HP cars could only run in Super/Stock for
1967.

Ford and Mercury >
Re-factored the 1966 'S-Code' 390/335 HP to {320 HP} for 1967
in the Ford Fairlane GT and GTA.

Pontiac >
Took the 400/350 HP GTO engine, and dropped it in their new Firebird, and rated it at {325 HP}.

Also, they popped the 400/360 HP 'Ram Air' GTO engine in the Firebird, and rated it
at {335 HP}.

Note; Pontiac adjusted the linkage for the Rochester Carburetor on the Firebird
400 engines to restrict the Secondaries from fully opening.

Note; That was the 'only' difference between the GTO and Firebird engines.