GM Motorsport, now operating as Australia Speed & Performance, offers comprehensive in-house performance packages tailored for Holden and HSV vehicles. These packages feature GMM V3 CNC-ported heads, a selection of high-performance camshafts—including the renowned Stealth, Street Racer, and Turbo Killer grinds—and full custom dyno tuning by Phonsy Mullan, a two-time world champion with over 30 years of racing development experience .