Don’t forget that the ID and DS engines have a cross flow head so the carb moves over to the other side of the car which makes it easier for fuel piping.
You may want to make sure that they are from a LHD car or you may have gearbox/clutch linkage issues like Mick has in his RHD Roadster (in a separate thread) to add to your list of ‘jobs’ to do.
BTW the inboard disc brakes really do stop a DS with the onboard hydraulics and if they would fit into a Traction, would transform it. It’s the 1st thing I notice when switching between cars.