Jim,
I'm going to put both blower curves here for you to look at. Ours develops 2 more inches of static pressure. At 8" of static, ours moves 1800 CFM while the Sheldon impeller only moves 1600 cfm at 2". As a matter of fact, when the sheldon or jet impeller reaches 12" static it is at 0 CFM. At 12" static, ours is still moving 1090 cfm. Big difference if you need the extra suction say thru a 2 1/2" hose for a dust nozzle.....to vacuum up places, or if you have long runs or a lot of fittings that build static pressure.