The Callaway SS features a supercharged version of the regular Chevrolet's 6.2-litre 'LS3' V8, boosting its output from 310kW and 563Nm to 425kW and 725Nm.
The performance gains leave the Callaway SS just shy of the high-performance HSV GTS, which produces 430kW and 740Nm from its supercharged 6.2-litre ‘LSA’ V8.
Facilitating the power and torque hike is the introduction of an Eaton TVS supercharger, liquid-to-air intercooler, increased flow-rate fuel injectors, high-flow intake system, and a low-restriction exhaust system.
Callaway estimates the supercharged SS will accelerate from 0-60mph (0-96.5km/h) in 4.5 seconds and complete the quarter-mile in 12.4sec, putting it just off the pace of the 4.4sec 0-100km/h and 12.3sec quarter-mile claimed by the GTS.
Other unique features of the subtly restyled Callaway SS include interior and exterior badging, embroidered floor mats, and branded key fobs.
The Callaway SS comes with an authenticity document as well as a three-year/36,000-mile (60,000km) warranty.
Callaway has a long history with Australian-made Commodore-based products. In 1998, HSV commissioned the Connecticut-based tuner to design, develop and produce the 300kW V8 for the 2000-2002 HSV GTS. A total of 1500 engines were produced by Callaway and installed by Holden under the partnership.
The supercharger pack costs US$18,695 ($20,400), making the Callaway SS US$63,165 ($68,900) as a complete package. The HSV GTS is priced from $92,900 in Australia.