Shouldn't need one...though i'm unsure on that style suspension. I havn't seen any asteric's on the 6" lifts for them saying a longer front shaft is needed. IDK.
Rear....swap to a 1piece and you'll be good to go. 6" lift kit comes with only about 4" of lift for the rear, and there's trucks out there with more lift running stock shafts without any issues.
Good to go on the rear if 1piece, unsure on the front shaft.