Eldorado — E-body (1983–1985)

Wikipedia's Cadillac High Technology engine article gives LT8 as the HT-4100's option code and lists the Eldorado, and its Eldorado article names the HT-4100 for this generation; the NICB Cadillac engine tables list a 4.1L V8 digital fuel injection engine (no RPO codes, so they do not name LT8; the VIN letter is not legible in the OCR text); no Buick or Oldsmobile E-body used this engine, so there is no sibling source

the Oldsmobile 350 cu in diesel; Wikipedia's Oldsmobile Diesel engine article prints LF9 and lists the Eldorado, and its Eldorado article prints LF9 in the generation's engine list and calls the diesel an option in all years (one Wikipedia source); shared E-body code, cited from the Buick Riviera: gnttype.org's 1984 Buick VIN table prints LF9 for the Riviera Luxury, sibling corroboration of the code, T3, which does not lift the row; the NICB Cadillac engine tables list a diesel V8 without an RPO code (the VIN letter is not legible in the OCR text)