You'll prob lose 8th gear on 35s with sport gearing and jeep will feel more sluggish. It's completely doable...simply depends on your ability to tolerate it.I have a sport JLU v6, to run 35's for mainly highway riding and occaisonal trail riding (light) is regearing needed? I currently have 33s and it feels fine. Everything is stock.
That doesn't do a thing for the manual transmission.When you say sluggish, have you re-calibrated the transmission for the larger tires using like a flashcal or tazer? As when i swapped my tires out it was so sluggish but just updating the software to the correct tire size brought it back to pretty much exactly what it was before. Might save you some bother.