its probably due to axle rap , when you accelerate the torque will change the drive line angle , i had a samurai with stock springs and an axle flip and it vibrated bad under acceleration because the stock springs were too weak , put an axle rap control bar on it and it was good , or you could change the pinion angle to acomadate for the rap , just my opinion with my experiences
dont the TG springs comes with that already?
