I did my 83 with the radiator in place. Get some good ball end allen wrenches and clean the bolt heads thoroughly. Only hint is to rotate the engine for installing the new one so the lobe is not pressing against the pump.

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Charles
1983 300D, bought new, 215k+ miles, donated to Purple Hearts veterans charity but I have parts for sale: http://www.peachparts.com/shopforum/mercedes-benz-cars-sale/296386-fs-1-owner-83-mb-300d-turbo-rebuild-parts.html