I just pulled the body lift off my truck this past weekend. You'll need 3" (if it's a 3" BL) shorter bolts, there's probably a steering extension that will need to be removed from the column, and you'll want to watch the brake lines, heater hoses, fan shroud, shifters and wiring harness to make sure that nothing gets pinched or kinked as the body is lowered. Otherwise, it's fairly straight forward.
A body lift does have an affect on the vehicle center of gravity,as does ever modification that is done. Add a heavy tool box, that will slightly raise the COG, add a suspension or body lift, that will raise the COG as well, heavy axles/rims/tires will help lower it, but being unsprung weight, its effect is calculated slightly differently.