Be wary of all manuals, people write all of those, and mistakes happen. Use what you have, but double check, and trust word of mouth more than manuals. Someone that owns the vehicle and actively works on it, probably knows more than any manual. Be nice though, we are trying to help each other.
I can tell you about a 351C engine and what oil capacity it has. But all manuals will disagree on those, the dipsticks changed for each engine model, though all oil pans were identical in dimensions. All Clevelands are listed as 5.0 quarts, yet the Boss and HO had different dipsticks, and took 6 quarts to show as full on the dipstick. Their oil pans had barely a difference in baffling, not enough to control another quart of oil. Those were aimed at higher rpm, and Cleveland engines were made with more oil flow to the heads(lifter bores had huge passages in them(the main oil galley)), thus needed more oil in stock form for higher rpm. That's just one weird example of manuals not being fully accurate or detailed with all needed information.