#1, That's a Fisher snowplow pump.
#2, It's a gear type pump, no pressure relief in it. Relief valve is in the control valve on this system.
#3, Water will rust the inside of this so fast you wouldn't believe it. If you let it sit for a couple of days, the bearings and gears will start to rust, and then you'll be pumping that into your engine.
#4, On a gasser that runs 1-1. I have gone 1 and 2 inches smaller and didn't hurt them any. I was using it on a plow though.
Hope this helps ya!
