Hey are the turbo and nonturbo 617 3.0 heads the same and interchangeable? I have a junkyard head was considering getting it rebuilt as a spare, is this doable by most machine shops? Those prechambers, anything special there? I saw a guy on ebay selling them for I think $90 a piece, wow. Obviously I would put rebuilt monark nozzled injectors as replacements. Any suggestions appreciated. My car 83 300D has 236K and could probably do with injector rebuild and fuel lines change.