We do drive in drive out engine conversions with LS barra, few diesels and other wierd and wonderful stuff. I have an m177 on the floor im trying to work out if a standalone setup is possible.
Been thinking about doing something with a w124 myself. Seema few LS swapped ones and there seems to be a lot of hassles with tunnel and steering, straight 6 would have to be more forgiving. Anyway Hartley 2790 location, look up LS Conversions on facebook if you want to chat about it.