All 1963 cars had 327cid engines, which made 250 hp standard, with optional variants that made 300 hp, 340 hp and 360 hp. The most powerful engine was the Rochester fuel injected engine. Options available on the C2 included AM-FM radio (mid 1963), air conditioning, and leather upholstery. Also available for the first time ever on a Corvette was a special performance equipment package the RPO Z-06, for $1,818.45. These Corvettes came to be known as the “Big Tanks” because the package initially had a 36.5-US-gallon (138 l; 30.4 imp gal) gas tank versus the standard 20-gallon for races such as Sebring and Daytona. At first, the package was only available on coupes because the oversized tank would not fit in the convertible. New for the 1963 model year was an optional electronic ignition, the breakerless magnetic pulse-triggered Delcotronic, first offered by Pontiac on some 1963 models.