The 1967 model year saw the introduction for the Pontiac Firebird pony car, a variant of the Chevrolet Camaro that was the brand's answer to the hot-selling Ford Mustang. Intermediate sized cars (Tempest, LeMans, GTO) were mildly face-lifted but all full-size cars and GTO lost their Tri-Power engine option though it did get a larger 400 cubic-inch V8 that replaced the previous 389. Full-sized cars got a major facelift with rounder wasp-waisted body lines, a name change for the mid-line series from Star Chief to Executive as well as a one-year-only Grand Prix convertible. 1968 introduced the Endura 'rubber' front bumper on the GTO, the precursor to modern cars' integrated bumpers, and the first of a series "Ram Air" engines, which featured the induction of cold air to the carburetor for more power. The Tri carburetor deletion came from the 14th floor of GM banning multiple carburetion and headed by GM president Ed Cole. The Ram Air V garnered much auto press publicity, but only a relative few were made available for sale. Full-sized cars and intermediates reverted from vertical to horizontal headlights while the sporty/performance 2+2 was dropped from the lineup.