1978 was the Corvette's 25th anniversary, and all 78s featured silver anniversary nose and fuel door emblems. A new fastback rear window was the most dramatic and noticeable styling change, giving the ten-year-old C3 Corvette body style a fresh lease on life. The fixed-glass fastback benefited both aerodynamics and increased the usable luggage space behind the seats while improving rearward visibility in the bargain. A shade was installed that could be pulled forward to cover the rear compartment to protect cargo and carpet against the unrelenting sun. The tachometer and speedometer were redesigned to match the new “aircraft styled” center console and gauge cluster first seen the previous year. Redesigned interior door panels were also new as well as an actual glove box was added in front of the passenger seat, replacing the map pockets of previous years. Available options now included power door locks, a power antenna, dual rear speakers and a CB radio. The optional convenience group, introduced the previous year, now included intermittent (delay) wipers, floor mats, and the passenger side vanity mirror was an upgraded illuminated unit. The quad headlights were changed from round to rectangular, and remained so for the rest of the generation's run. The base L-48 engine generated ; Those destined for California or high altitude areas produced . Gone was the chrome-plated ignition shielding over the distributor, replaced with a metal-lined black plastic unit. The single-snorkel air intake used since 1976 was changed to a dual-snorkel set-up on L-82 equipped cars helping to boost that output to . L-82 engines were also now fitted with an aluminum intake manifold which saved 24 pounds compared to the cast iron unit of previous years. The Corvette converted to metric tires with the P225/70R15 as standard. Wider P255/60R15 tires were available as an option and required fender trimming from the factory for clearance. The fuel tank capacity increased from 17 gal to 24 gal on all cars. To make room for the larger tank, a smaller (P195/80D15) space saver spare tire was utilized.