Hello Gerard, I upgraded my 230 SL to an M130.980 engine also. At the same time I also upgraded to the vertical side mounted oil cooler. This required widening the radiator bay. To accommodate this, it was necessary for me to fabricate a new radiator support, which I then riveted in place. The salvage yards have many 280 sedans from which you can cannibalize the necessary oil lines and filter housing to do this modification.
Good Luck, Larry in CA