Rear End Swap Valve Needed?

[Spray'dV6]

I did a search on the board and read where people suggest buying a new valve of some sort when doing an axle swap??? What valve would that be? As far as I know this is all I will need...backing plates, brakes lines and hoses, calipers, rotors, pads and that is it. Am I missing something here? It's a 99 t/a 3.42 posi rear without traction control.

[Backfire]

The front/rear proportioning valve is different between a disc/drum car and a disc/disc car. I think the disc/drum valve sends more braking force tothe rear drum brakes since the drums are less efficient. So when swapped to a disc/disc setup, you will get more braking from the rear discs than someone with who has the intended valve. I think that is the case, although I could have the two situations backwards. I don't know the actual values or what kind of a difference they actually make. Considering you will be using the LS1 rear brakes with the LT1 front brakes, a new valve from an LT1 disc/disc car may still not balance the two as intended from the factory. I know some have done the swap without the valve, while others say you need it.