The pulley is a press fit and it is very tight on the shaft. I also found it easier to change the pump as I didn’t have a press at the time. I have switched the pulleys since on my parts pumps. In order to do so, I had to build a puller apparatus. You likely have the earlier style 1/2” pump pulley on your pump. Do you have a press? The means to build a pulley?

Last edited by Fox; 08/06/2018 1:57 PM.

1970 Chevrolet C10
Grandpa's -- My first truck -- In progress to shiny
Follow the build in the Project Journal
1950 Chevrolet 1-Ton Dually
"Ole Red Girl"
In the Stovebolt Gallery
More pictures here
1951 GMC 9430 1 ton dually--Shiny! | 1972 Chevrolet C20- Rusty- the puzzle box lid for the C10 | 1962 AMC Rambler American- my wife's
Parts trucks-
1951 GMC 9300 | 1951-GMC 9430 | 1951- Chevrolet 1300