The Mother Lode coast redwood is beyond a "Stovepipe". The Stovepipes are redwoods with minimal trunk taper. One of the biggest stovepipes of the last century was Crannell Creek Giant with tremendous volume. Others of varying sizes grow in the redwood parks. Those are the ones where the line of the trunk sides may seem rather parallel if they are straight.
In addition to huge diameter, the Mother Lode exhibits some reverse taper. It was one of several new discoveries including Grogan's Fault, Dog Soldier and Maximus found with the aid of back doors like Hilton's Rd. SW Orick where the access gate leads to a network of gravel or abandoned roads.