Originally Posted by jtphoto JK

6" lift with all stock control arms? it is likely that the driveline vibe is going to be the least of your worries. Once you minimize your pinion angle you could be into the - caster range which means on road handling may be dangerous. Are the springs bowed as well. Do you have the stock front axle housing?

In all honesty I don't think anything other then cut and reweld Cs and springs seats is gonna fix your problems.