Sweet have you got the root or screw type charger?
And you have already upgraded the heat exchanger have you put a larger cooling rad in too so that you have more water in the system?
Just gonna get curious on this as ill be having to play with a 32v 4.6 at some point in the near future and they guy wants to put an uprated screw type charger on it 2.6l one if i remember right from Kenny Bell