"As he points out, his conversions consist almost entirely of taking stock GM parts and snapping them together in clever new ways. 'They could do all this stuff if they wanted to,' he tells me, slapping on a visor and hunching over an arc welder. 'The technology has been there forever. They make 90% of the components I use.' He doesn't have an engineering degree; he didn't even go to high school: 'I've just been messing around and seeing what I can do.'"