The mounting position for the expansion tank should be on the passenger side about midpoint on the fender. I don't know what's there on a 240, but there are brackets for mounting it in a 300. The mounts for the turbo radiator on the passenger should be the same, but it's about a 6" wider radiator. And the oil cooler mount may be different, it seems I've seen some different types of oil coolers in this chassis.

__________________
1985 300D-189k The 'UD', Ivory and Pinkamino
1979 300D-211k Dark Gray, Parchment
A 1980 Harley-~166k and
A 1994 Ford diesel pickup-349k and
A 1990 gasser Volvo wagon-145k