IanC is correct. However you did not give a serial number for your 770. As many years as the 770 was produced there were three different styles of power steering pumps and two different types of power steering gears. The later ones had full hydrostatic steering. The first ones had a pump run off the generator similar to a 57 Chevie. The later ones had a pump similar to a later Chevie and belief it or not, But both of those pumps have a filter on the inside!
Hydrostatic steering (no steering shaft going to the front wheels is different yet and uses a different pump. This was also available as a &amp;quot;kit&amp;quot; to update older 770&#039;s that had the old style steering. Questions?