Did you know....that on paper...the 400 WZ was 330 HP and the 1969 WQ RAIII was 335 HP?
The paper lied...
But the difference wasn't just 5 HP...more like 35-50. The difference was in the 068 cam (Firebird) or 744 grind (GTO) springs, carb jetting, long branch exhaust manifolds.
Doing one without the other is pointless. You can't just swap out the #16 heads for the 48's and expect results.
Swap the 16's for the 48's only? NADA.
Swap the cam and keep the 16's...20-30 HP.
Swap the cam and springs 30-35 HP
Swap the cam, springs, exhaust...40-50 HP
Refresh the existing heads with new valve job...and the above 50-60 HP.
A caveat...these are old world numbers with high octane fuel. Deduct 40% from the above numbers running 93 octane.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
