Hello, I have an early 990 David Brown, I think my grandfather bought it new maybe late 60's. A few years ago I ran biodiesel in it and let it set for over a year. The fuel got gummy, plugged the injection pump. I thought I would just swap out pumps, someone gave me a newer DB with a motor that is shot, the injection pump came off easy. On my older DB, the power steering pump is on the same side in front of the injection pump, unlike the newer one on the opposite side. The pump looks the same, can I swap them? and, how do I get that pump off? Do I need to take off the power steering pump first? thanks