Swapping SA 431 and SA 3200

Can someone shed some information if there would be performance gain to what I'm planning to do?

We have a Smart Array 3200 with Ultra3 drives in an ML370G1 and an SA 431 with Ultra2 drives in an ML350G1. My plan is to swap the controllers such that Ultra3 drives in ML370G1 will have an Ultra3 controller (SA 431)and the Ultra2 drives in ML350G1 will have Ultra2 controller (SA 3200). Both servers would eventually function as DCs, File & Print Servers in an Win 2003 environment with the ML350G1 to serve 30-user branch office.

Thanks in advance.