Instead of searching for "Workshop Manual," try searching for "Isuzu 4HF1 Engine Shop Manual PDF" or "Isuzu 4H Series Workshop Manual."
You can find workshop manuals for the 4H series (which includes the 4HF1) and related 6-cylinder models through the following platforms: Isuzu 4H | PDF - Scribd isuzu 4hf1 workshop manual 6 cylinder pdf
When searching for this manual, ensure the file includes the "General Information" and "Engine Mechanical" sections. Many "clipped" versions online remove the valuable specifications for bearing Instead of searching for "Workshop Manual," try searching