This is the blower I have.. (broken link removed to http://www.americanenergysystems.com/Stock/LibraryFiles/MF3650ExhaustBlower2-speed.pdf)
Says 2 speed.. I have it hooked up so it runs the higher speed.
Also, how tight does the ash pan door have to be sealed?
The ash bin seal if gasket-ed should pass the same test as the door test.