Chainsaw Repair

That's a normal observation - the 68dl 3/8" Husky mount bars simply are longer than "called", when the bar manufacturer follows Huskys specs.

64dl ones (also called 18") exist as an alternative, at least in small mount (K095). These really are 17" bars, like the 72dl bars called 18".

The "called" length of a chainsaw bar very seldom is accurate - and shorter than called is much more common than longer. Those 68dl bars represent a very unusual exception.