The Monaro GTS continued to be available as a coupe or sedan with 253 cu in (4,150 cc) V8 power, or the optional 308 cu in (5,050 cc) V8 engine. The GTS sedan was now a model of its own—in HQ the GTS sedan was an optioned Kingswood. The Monaro LS coupe also continued within the range, but still with the 3.3-litre six-cylinder engine as its base power unit.
The body paint-outs were discontinued in the HJ Monaro GTS range, but for the first time, the Monaro could be dressed up with optional front and rear spoilers. It seemed that Holden were no longer interested in promoting the Monaro GTS coupe as a performance machine and this became all the more obvious with the HJ coupe series having retained the HQ model's rear body styling.
The HJ Monaro LS coupe is close to being the rarest regular production car ever made in Australia with only 337 units produced. The HJ Monaro GTS coupe was discontinued during 1975 due to falling demand, 606 examples having been produced.
Some references show the HJ 308 produced 250 BHP
A run of ADR27A engines was introduced in late production HJ vehicles in April - May 1976 at the Pagewood plant, as a pilot for the forthcoming HX models for which ADR27A emission control systems would be mandated. The power level of these engines was lower than earlier HJ engines;