fan wall

Hey everyone I need help. I have a Norco 3216 3U server that has a 4x 80mm fan wall. http://www.norcotek.com/product/rpc-3216/ Norco sells a 4U 3x120mm fan wall for the 4U servers 120mm fan wall bracket for RPC-4224, RPC-4220, RPC-4216, RPC-4116, RPC-4020, RPC-4164 I know that there is a 3U fan...