I recall a member doing that, I was going to put one in my '87 300D.
It should fit under the radiator, would require a different entrance to the intake manifold than the existing one. So I got a intercooler from a W210 and the hoses but never did anything towards that goal. It would help the OM603 a lot.
see this thread:
https://www.peachparts.com/shopforum/diesel-discussion/99215-someone-finally-intercooled-om603.html

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!