The Unimog and MB-trac enthusiast communities are fanatical. In the files section of the "OM422 Owners Group" (Facebook), users often share scanned copies of the "Engine Section" of the Unimog 427/437 workshop manual. This is the same engine block.
You want a digital copy that is searchable text (OCR), not a photo of a dirty page. Alternatively, look for the original Mercedes-Benz factory binder (Paper number W 42 1/...). om422 engine workshop manual
: If you're unable to find an original copy, you might consider a reprint or reproduction of the manual. Some companies specialize in reprinting vintage or hard-to-find manuals. The Unimog and MB-trac enthusiast communities are fanatical