Well I did a search at Summit, and at least the Hooker Headers p.n. 2457 showed applications to include (1) 1969 BelAir (your car, eh?) and (2) 1967-69 Camaro and (3) 1968-69 Chevy II (a.ka. Nova) as applications, so I would say, probably, but depends on the manufacturer.
Where are you sourcing these? And who told you what? And will they back up what they said?
Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod