by MECOA » Wed Feb 22, 2006 8:49 pm
MO is MD if you look closely. MD = ModelerDirect
Before MECOA bought K&B they started Modeler Direct to sell off inventory and hence they marked a lot of the items sold thru Modeler Direct with an MD
As for the shorter lug. Someone at the old K&B decided that the exhaust should be shortened to allow better access to the mounting lug screws and they also went to a 6-32 thread rather than the 5-40 used before.
Check your screw thread and see if they are the same old and new. Also do you have the newer muffler design?