The Pacer featured the familiar 225 Slant Six. The Pacer version of this engine was modified to a rating of 175 hp at 5,000 rpm, utilizing a new two-barrel induction, a split exhaust manifold, and a compression ratio boost of nearly a full point to 9.2:1. Adding visual spice to the package, the Valiant Pacer's suspension was significantly lowered as compared to the standard VF Valiant, and the exterior was dressed with special wheels, a blacked-out grill, side stripes, Pacer 225 decals, and a choice of four high-impact colors. Inside, high-backed bucket seats and a tach added to the performance feel. The Pacer offered performance capable of keeping with most standard V-8's of the time, though it posed no threat to the established musclecar top gun. The Pacer did mark the first Australian performance-orientated machine designed for the mass market at a bargain price. Most significantly, the Valiant Pacer was indicative of Chrysler's future efforts in the Australian musclecar market.
In June 1970, Chrysler Australia introduced its revised Valiant line-the VG. From a styling standpoint, the VG Valiant followed its predecessor the VF, still bearing the familiar lines of the American Dart/Valiant. Coinciding with the unveiling of the VG-series was the real news-the introduction of a new engine, the 245ci Hemi 6. Early engineering development for this powerplant had its origin in the United States, reportedly a design slated as a heavy-duty six for truck applications. The project was scrubbed in the United States, and Chrysler Australia took advantage of the groundwork for the basis of their own Australian-manufactured engine.
Although the roots of the design were in the framework done in the United States, Chrysler of Australia carried out the major development and financing in creating the Hemi 6. With an investment of 33 million dollars (unheard of for an Australian auto manufacture at the time), over five years of development, and a reported million test miles, the Hemi 6 was a powerplant that Chrysler Australia could call their own. The Hemi 6 represented Chrysler of Australia's finest hour, without a doubt the supreme inline six offered by a major Australian manufacturer at the time, with power that matched most of its competitors V-8 offerings, but with better fuel economy and at a lighter weight. The Hemi 6 architecture departed from the four main bearing slanted configuration of the American Slant Six, in favor of an upright block with a beefy seven main bearing bottom end, and a large bore combined with a moderate stroke. The cylinder heads provided excellent airflow, particularly compared to other contemporary engine designs, but Chrysler of Australia undeniably took a healthy measure of poetic license with the Hemi designation. The chambers were a canted-valve-wedge design, rather than a hemispherical configuration. The engine's design presented a far higher level of potential than the engine it replaced.
With the VG Valiant, Chrysler Australia continued the Pacer as their performance leader. Standard power for the Pacer Valiant was a two-barrel version of the all-new Hemi 6, delivering 185 hp. The 245-powered Pacers were a second and a half quicker than the earlier Slant Six-powered Pacers, but that was only scratching the surface. With their new engine design to play with, Chrysler of Australia was getting serious about performance. Having withdrawn from the '69 Bathurst race as a protest over class rule changes, Chrysler was looking towards the '70 event armed with an arsenal of regular production options aimed specifically at road racing.