I’ve installed Badass high-mass bridges in every bass in my collection that will take them. Why? I love ’em to death for their beefy sustain and definition. That said, they often come without string slots cut. This doesn’t exactly make them a drop-in mod, they’ll need some handiwork to install. I avoid the pre-slotted bridges, as cutting them yourself allows you to get a perfect string spacing and fit for your particular bass. If you’ve got an unslotted Badass bridge (or one of the recently-available Omega bass bridges from Allparts, which from what I can tell are exact replicas of the Badasses, even constructed w/zinc), here’s a rundown of how to install them.
UPDATE: re-edited this in January 2017 to add pictures (finally!) from a new build. Also note- if you’ve got an Omega bridge, these steps should also work.