Depends on how far you want to lower it. Greg's new shackles will drop you about 3/4", but he's got replacement leaf springs that will get you down further. See his website here: http://www.prgproducts.com/titan_lowered.php
Edit: Thread about Greg's shackles here: http://www.titantalk.com/forums/titan-suspension/68480-prg-shackles.html?highlight=prg+shackles
Edit: Thread about Greg's shackles here: http://www.titantalk.com/forums/titan-suspension/68480-prg-shackles.html?highlight=prg+shackles