Forget about the HUMMER H1 Alpha with the 6.6L Duramax. The cheapest version costs more than $129,000, and that's not including tax, title, and options. Why shell out more than you'd pay for a new Porsche 911 Turbo when you could buy a used Hummer H1 and take it to Sin City Motorworks for one of their 6.5L upgrade kits? The shop's High Performance packages can bring the non-Duramax Hummers to life with up to 320 hp and 510 lb-ft of torque. Here's how they do it.