You could get away with using "log manifolds" which were of poor performance on a GTO and Firebird, with exception that you would have to reroute new downpipes from manifolds back.
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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.