I was in the same situation. I removed many bullhead (BH) and stocked LMB. Two years later, the average size of the BH appears to be increasing. The bullheads I caught this year average about 8". Still not quite table size. Here are a couple links to previous discusions:

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=002503#000008

http://www.pondboss.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=20&t=001862&p=0