The Welder Up tour bus receives an interior steampunk makeover, while Merlon converts the engine to run on vegetable oil, and Travis installs triple turbos. Meanwhile, Justin drifts into unfamiliar territory with his '62 Lark.The Welder Up tour bus receives an interior steampunk makeover, while Merlon converts the engine to run on vegetable oil, and Travis installs triple turbos. Meanwhile, Justin drifts into unfamiliar territory with his '62 Lark.