This information is from another discussion forum FOUND AT THIS LINK .
The 9 at the beginning means that it is a row crop chassis and that it has the 172 ci engine. The 6 in the middle means that it has a 5 speed transmission and a two stage clutch with live PTO. A 5 in the middle would also be a 5 speed transmission, but it would have a single stage clutch and non-live PTO. The 0 at the end of the model number means that it was part of the "hundred series" of tractors that were made from 1954-1957.
The -5 at the end means that it had a factory wide front end when it left the factory.