The HX was introduced in July 1976 and was basically a cosmetic upgrade on the HJ, although one major reason for the release of the HX was the introduction of new anti-pollution requirements, Australian Design Rule 27a, to lower exhaust emissions. But the addition of emission control equipment without any re-design of the basic engine saw reductions in both fuel efficiency and power output.
The cosmetic changes included a much better grille treatment than was afforded the HJ, bright colours, large GTS decals, colour-keyed mirror and bumpers, integrated body-coloured spoiler options and optional bonnet black-out made it the most distinctive of all four door Monaros. But perhaps the most little known feature of the HX was the somewhat primitive anti-lock braking system introduced. The system only operated on the rear wheels, which naturally dimished most of the potential safety benefits such a system would bring. But the HJ retained the longevity and built-in toughness of the HQ series while adding greater comfort and extra appointments. As new emission controls killed off many Australian performance car favourites, the HX Holden Monaro GTS was also one of the few to keep the V8 muscle car tradition alive.

Item includes certificate with individual production number.