I found a 2:1:1:3 ratio of bourbon, triple sec, lemon juice, and Vernor's ginger ale (omitting syrup entirely) was sufficiently sweet without being overpoweringly so.
Came out pretty good, very well balanced flavors! I agree with the other commenters that as is, it was just a tad sweet. I also used an extra dash of Fee Brother's, as in my experience 1 dash doesn't provide sufficient foam in the end drink.