After reading through countless threads about long tubes, I still don't have a definite answer about tuning. I'm wondering if a dyno tune would be necessary after putting them on?
P.S. I do have a Xcal II that i bought with my JLT cai that has a canned tune.
Yes, any exhaust mod from the h-pipe foward will need some sort of tuning either by dyno, or by contacting your sct dealer with a list of current mods, so they can try to make you a new "canned tune" that would be safe on the engine, but a dyno would be the way to go.