One of the first upgrades people do with 606 swaps is fitting a sump from the later OM648-engined Mercedes cars. This is done to give more clearance to the front axle and is definitely worth doing although prices for the sump and different oil pump needed can be very high and they're quite hard to come by.
The bolt pattern in the OM648 sump is different to the standard OM606 sump and most adaptor plates have different holes to accommodate for this. Because we're using a Mercedes bellhousing, tabs have to be welded onto that to accommodate the different sump.
Maybe overkill but worth doing it right in my opinion!