The term "tall gut" is quite rare and not commonly used in everyday language. However, one could consider using synonyms to convey a similar meaning. For instance, "slender build" is a suitable substitute, emphasizing a person's slim physique. Another option could be "lean frame", which implies a thin and well-proportioned body. Additionally, the term "towering stature" can be used to describe someone with an impressive height. It is important to note that these synonyms may not entirely capture the precise connotation of "tall gut", as this phrase seems to be quite specific and unconventional.