LM7 [GM Gen III 5.3 V8] considered to be one of the least troublesome V8 engines on the planet.
Better reliability record and lower customer problems than Merc and BMW types.
Perfect replacement for the old Rover V8. You can buy the 4.8 (LR4) for about $400 from salvage yards in the U.S. They make 270-290hp & 280-300lb-ft on just the factory tune.
2007 LM7 uses E67 controller (PCM). The ETC parameters easy enough to delete but you'll need a pre-2003 LM7 for a cable TB.
Give me a shout if you need any help.
