Story
1970 Holden Monaro
Holden introduced the HG Monaro on 26 July 1970 as the final version of its original pillarless coupe. Regular Monaro, Monaro GTS, and GTS 350 configurations remain together on this family page so their engines, transmissions, chassis, paint, trim, and identity boundaries can be compared without duplicate pages.
Regular Monaro, GTS, and GTS 350
The 80337/80437 regular Monaro used restrained trim with six-cylinder or Holden V8 power. The 80737/80837 GTS added sports instruments, console, bucket seats, sidewinder stripes, hood scoops, black rocker treatment, badges, wheels, and standard power front discs. The 81837 GTS 350 paired its model-specific identity with Chevrolet 350 power, Saginaw or Powerglide, Salisbury limited slip, and GTS 350 chassis equipment.
Six engine paths
The reviewed 1970 range covered 161, 186, and 186S Red sixes; Holden 253 and 308 V8s; and the Chevrolet 350. The four-speed 350M used 10.25:1 compression and a 300-bhp rating. The Powerglide 350A used 9.0:1 compression and a 275-bhp rating. Displacement, decals, or an engine swap cannot establish the body model or born-with configuration.
Manual, Trimatic, or Powerglide
Regular applications used three-speed or four-speed manuals or the new three-speed Trimatic according to model and engine. The GTS 350 was the exception: its manual path used a cast-iron Saginaw four-speed, while its automatic path retained Powerglide. Motorsport Australia's historic form explicitly says a Muncie was never factory fitted. Gearbox, controls, pedals, floor opening, axle, dates, and records should agree.
Axles, brakes, and touring suspension
Regular powertrains used GM-H banjo axles with application-specific ratios and optional limited slip. The GTS 350 used a Chevrolet Salisbury 10-bolt limited-slip rear. Regular six-cylinder Monaros began with drums, while V8 and six-cylinder GTS configurations used power front discs. HG retained rubber-bushed control-arm front and leaf-spring rear suspension but moved the GTS line toward a more compliant touring calibration.
HG appearance and cabin
The HG is recognized by its fine-mesh divided grille, reduced brightwork, pillar script, and lack of wheel-arch moldings. GTS sidewinder stripes followed the upper fenders and beltline, with delete available. GTS 350 used bolder 350 decals and black scoop treatment. Inside, sports instruments, console, bucket seats, steering wheel, and optional houndstooth trim still require body-plate, material, and order evidence.
Production and identification
Reviewed references report 6,147 HG Monaros across the full July 1970-July 1971 series. They do not provide an audited 1970-only count or splits for regular Monaro, GTS, GTS 350, engines, transmissions, paints, or trim. Start with 80337, 80437, 80737, 80837, or 81837 identity, then reconcile the shell, chassis, engine, gearbox, axle, brakes, suspension, paint, trim, dates, and ownership history.
Native Australian values
Introduction prices were A$2,765 for Monaro, A$3,323 for GTS, and A$4,174 for GTS 350. Later Australian auction observations are also denominated in AUD. The current structured pricing contract supports USD and CAD rather than AUD, so those figures remain cited gaps instead of being mislabeled, silently converted, or presented as appraisals.