I now have the blower running about 30% faster than it was running with the standard pulleys.  The single phase, 15 hp motor is now drawing about 40 amps.  It was more accurately drawing about 30 amps before.  The dryer is now discharging at about 300 bushels per hour instead of a little over 200. 

This seems to be working for now.  All it needs to do is hang together for another 80000 bushels.  I will otherwise be looking for another pump a little sooner than I had hoped.  Thank you for your suggestions.