A Lot of Shadiness
While you get along famously in the platonic realm, your camaraderie might not transfer over well to the BF-GF realm. Sure, there's a chance for romance, but you could just have an ideal friendship. If you have your heart set on transforming your BGF into your BF, go for it. But if you'd want to salvage your friendship if the romance sours, proceed with caution.