Thanks to Harold H and a question.

Perusing the IH archives on YT, Harold H posted figures for the W9 as 52.36 BHP corrected for sea level. Aha! There's the answer.

How do you find out the "corrected for sea level" figures? Do you need to purchase the individual tests from NU for this information? My book "Nebraska Tractor Tests from 1920", by C.H. Wendell does not have "corrected" figures. Is there a correction factor that you can apply to the figures in Wendel's book?

All of the Nebraska tests prior to somewhere around 1960 or 1961 gave the observed HP results along with all of the weather conditions at the time of the test. They then calculated the results based on sea level, 60 degrees F. and 29.92" Hg. These calculated results were the corrected horse power CHP. Sometime in the early 60's, I'm not sure of the exact date, for some unknown reason they just started giving the actual results and not calculating the corrected for sea level horsepowers CHP. For example on Farmall tests, the 340, 460, 560, etc all show both the actual test result HP the CHP whereas the tests on the 504, 706, 806, etc. only show the actual test result horsepower. The first mentioned group were tested in the late 50's and the second mentioned group were tested in the early 60's.

Harold H

C.H. Wendel had compiled a list of MBHP figures in an Appendix in his book indexed by fuel economy figures. Beginning with Test #0684, the listed MBHP figures jive with Test C for MBHP described in the text for each test unit. Figures prior to 1959 do not square up exactly.

What are the corrected for sea level figures for the Farmall 460 Gas, 504 Gas, and 400 Gas?