The problem is you'll never get an engine dyno run to compare what the manufacturer puts out. I'm not gonna pull my engine to find out as most people won't. There is loss in the driveline when you do a chassis dyno as the transmission eats up some of the HP.
A standard rule is you lose "about" 15% from a manual and 20% from an auto. This is not an absolute by any means. I don't know what the standards are either. High performance shops run a header but not a full exhaust when they do an engine dyno. They also tend to run it with an electric water pump with no belts attached. They do this for their own consistency from engine to engine, not to mention the extra time and space involved to run the other components. All these differences will impact the final numbers.
My 2004 4x4 manual dyno'd 180.xx to the wheels. Take 205 Engine HP, less 15% and it comes out to 174.
2004 Ford Ranger Sonic Blue 4dr 4x4 4.0 Manual