B Bob Dunahugh New member Sep 17, 2012 2,784 4 3 Sep 10, 2018 #1 The ducts in this 73 seem to be 3-1/2". Not the normal 3, or 4". 3-1/2 don't exist that I know of. Bob Dunahugh
The ducts in this 73 seem to be 3-1/2". Not the normal 3, or 4". 3-1/2 don't exist that I know of. Bob Dunahugh
