MEM_ATC-
Thanks for the info. It's been a long while since I looked at the 7110, but refresh my memory what classifies as small / large and where the line is. IIRC its 41K right? For some reason I thought it was 3 behind large, 5 behind heavy. But now that you mention it 4 seems to ring a bell.
Guess it's all the years of flying a "small" large category airplane (CRJ) that muddles things up...