SBR, 888, BJR and PCR use SBR developed Ford V8's, while HRT, HSVDT and Perkins Engineering use HMS developed Holden V8's while the rest of the Holden teams use their own developed Holden V8's) leading to minor/major (depending on teams) engineering differences among teams despite the cars being the same make.
Different teams employed SBR-developed Ford V8 engines (SBR, 888, BJR, and PCR), whereas HRT, HSVDT, and Perkins Engineering utilized HMS-designed Holden V8 engines. The rest of the Holden teams developed their own Holden V8s, leading to varying engineering differences among the teams.