I believe it mentioned it as a route that had no height restrictions on it directly, and had no weight limits on it indirectly (the Southern has a direct height restriction due to a bridge somewhere in Tinton Falls, and an indirect weight restriction due to some NJT restrictions on the Coastline). This line has been abandoned for the better part of 30-40 years, so I seriously doubt that NJTPA was able to do extensive studies on this section of track, especially with the overgrowth.
There are some bridges on the Southern and FIT that are about as old as that bridge by Gold's Lumber, and they can support current trains + more, so that bridge should be fine?