As JHolloway and Bronco Junkie were saying 77 Bronco, your year is not always as simple as just adding springs. Yes the general rule is for 2.5" you might not need any other stuff (even if you "should" use it), but that's for the earlier models with the "Inverted-T" style steering. Yours has the '76/'77 only "Inverted-Y" system. And it's not as forgiving of it's angles being changed.
At the very least, you need to have your toe-in readjusted, but even that's just a hit-and-miss thing. Most owners that do the taller lifts just automatically change their whole steering linkage to the other style. Some continue to use the "Y" setup, but as always... Your Results May Vary.
One thing you could do now though, since it sounds like it's drivable, is to take it to an alignment shop and get a printout of your existing settings. You really want to know what your caster angle is for starters. That way you can decide which C-bushings are best for you. Most early Earlies need more bushing than is expected, but after sometime in '75 or '76, things started getting corrected at the factory. But it's still best to know for sure.
As was mentioned I think, you can slowly do one thing at a time, but be ready willing and able to make more additions to your parts pile if your Broncos doesn't like being lifted. At a minimum, you'd probably want the adjustable trackbar, but since adjusting the draglink is so critical to a lifted truck (and your stock one is not adjustable) you might be into it for a more adjustable linkage setup.
Wait for a few more of the '76 and '77 owners to chime in with their experiences before you pull the trigger, and definitely do a "before-and-after" alignment check. It's money well spent and some even get the printouts for free since the alignment guy doesn't have to adjust anything the first go-round.
Paul
