We’re currently in the third generation of the 5.7 HEMI^® V8, an engine that you’ve known and loved for two decades now. To our benefit, constant upgrades throughout the years have improved both performance and fuel economy, among other things. Now, as many early-day HEMI engines approach the end of their normal life expectancy, the demand to repair and refurbish these future classics intensifies. A 2011 Dodge Challenger R/T with a five-speed NAG1 automatic and a history of things gone wrong – including the timing chain unexpectedly snapping at 66,000 miles and choppy repairs – is today’s guinea pig. An eventual failure of head gasket integrity around 235,000 miles brought this Challenger to IMM Engines in Moreno Valley, California. Johnny Hunkins talks us through disassembling the HEMI engine in part one of this story and is letting us tag along to put it back together in part two. This how-to is a step-by-step, complete with video, part numbers and quoted costs. You may want to bookmark it for your next repair.