TC factory pistol Lug spacing on 14" barrels is 3-1/4", as factory issued.
TC factory Carbine (rifle) lug spacing is 3-9/16".
Quite a few custom barrels are floating around that use either (and sometimes neither), but if you are wanting a factory forend to fit the longer, you will need the carbine forend....NOT the super 14.
There is no distinction between the 14"/super14, all use the pistol lug spacing, unless special ordered/custom built; such as some by the TC custom shop on special request. A few carbine barrels were built using pistol lug spacing at the request of the TC Collectors Association.
i snapped a pic below of the lug setup used mostly on carbines:
As measured from the rear of the barrel lug, first lug is usually set at 3.5" from lug face, and the frontmost lug is at 7-1/16"...
make sure your lugs are spaced as below, if so the rifle/carbine forend should work.