I just completed framing this 12x24 lean too addition off the back of my shop. I lag bolted a 2x10 to the wall at the double top plate. Used 2x8 rafters and did use joist hanger under them as well. I'm just under a 4/12 pitch on the roof.
Ya it's stamped in the aluminum on the pump. I ordered a rebuild kit for it about 6 years ago....head gasket went. I have the info in the shop. Will get it tomorrow for you