The iron intake and exhaust manifolds were unique as was the 735-cfm Holley carburetor. By mid-’67, the 428 “Cobra Jet” had advanced to the testing stage and Ford engineers liked what they saw.

The Cobra Jet’s intake manifold was made of cast iron and topped ... A unique feature of 1968½ 428 Cobra Jet-equipped cars was a starter delay relay, which would interrupt power to the starter ...