Headlights: Don't even think about going higher than 54 inches. However, keep in mind that the original suspension cannot be "disconnected", but don't let that stop you from bolting on heavy-duty shocks and overload springs. Other need-to-knows: Don't remove or disconnect the ABS, and the tires can be only two sizes larger than the manufacturer's recommendation. Spring-shackle extensions are also a no-no.
Two sizers larger than "factory recommend" means 33 inch tires haha. Because I believe factory recomennded ALWAYS means fx4 lvl 2s that come with 31s.