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.
Really nice summer drink. To make use of ingredients on hand, and to boost the ginger component, I used 2 oz Bulleit "95" rye, dropped the syrup, and added 1 oz Barrow's Intense Ginger. This was really good even without any ginger ale. Add ginger ale to make it sweeter and easier to chug down in a one-er.
Drop the added sugar but use limeade instead of lime juice and fill your tall glass with Bundaberg Ginger Ale (which is already loaded with sugar) and you have a really delicious drink.