Re: Tow Rig Delimma
Looks like the L76 debuted after the LQ9 was referred to as Vortec Max, in half tons. This article also mentions a "Holden L76 engine" so you may be on to something there. I'm not familiar with Holden. Also believe the 09 was the last year Vortec Max was available.
L76
The L76 is derived from the LS2. And like the LS2 it features an aluminum engine block. However, the L76 does feature Active fuel management (AFM). While the displacement on demand technology was disabled on Holdens, this feature is enabled on the 2008 Pontiac G8 GT and subsequently refitted in the 2009 model Holdens with AFM enabled, but only on models fitted with the 6L80 Automatic Transmission. The engine also meets Euro III emissions requirements. Output is 348 bhp (260 kW) at 5600 rpm and 376 lb·ft (510 N·m) at 4400 rpm for the Holden variant, and 361 bhp (269 kW) and 385 lb·ft (522 N·m) for the G8 GT.[11] The Vortec 6000 or new VortecMax version is based on the Holden L76 engine, and features variable cam phasing, along with Active Fuel Management. It can be considered the replacement for the Generation III LQ9 engine. It produces 367 hp (274 kW) at 5400 rpm and 375 lb·ft (508 N·m) at 4400 rpm. Production of the Vortec 6000 started in late 2006, and is only available with the new body style Silverado and Sierra. The final year for the option of the VortecMax engine was 2009 in the Silverado and Sierra. vin code (Y)
Applications:
2006 Holden VZ Commodore - Those built from February 2006 until July 2006 until the release of the VE series.
2006 Holden WL Statesman/Caprice - Those built from February 2006 until September 2006 until the release of the WM series.
2008–2009 Pontiac G8 GT
2008–2010 Holden VE Commodore (automatic only)
2008–2010 Holden VE Ute (automatic only)
2008–2010 Holden WM Statesman/Caprice
2007–2009 Chevrolet Suburban
2007–2009 Chevrolet Avalanche
2007–2009 Chevrolet Silverado
2007–2009 GMC Sierra
2007–2009 GMC Yukon XL