You can use 4600 for the fronts because the torsion lift is just taking out downtravel of the suspension, meaning it's the same length. But adding an extra inch to shock length in the front wouldn't hurt. You can use Bilstein Universal 5100 Shocks and just measure out the length for the front and back. Or if you wanna go real hard, get some 5165 Universal Reservoir Shocks.What bilsteins work with a 3" lift? I'm assuming it's just a torsion twist lift he has. Are oem size long enough?