Fool, did you even check all the link I posted up top? I am basing my estimates on the test result on this site. http://bob123e.tripod.com/thegreatheadertest/

Laugh all you want but that ITR is putting out 176 to the wheels, and the best header they've tested got it to put out 190 to the wheels. From 176-190 is 14 hp. Pretty close . There are other header, such as custom engineered or drag header that could add more than that. Also since you quoted me correctly, you should be able to read that I put "maybe?" at the end of that statement.