57 trim with .48 a/r IMO would be best for you. I dont think the turbine housing size will make you go flat up top unless you plan on running alot of boost. which I dont think you will need to for 330hp. Most all KA's go flat up top no matter what turbo you have. Below is my dyno from last year at low boost on a 50 trim with .48 a/r @ 14 psi I didnt take it past 8000rpms on this chart. The torque curve didnt show any signs of a .48 a/r turbo. However on long highway trips the turbine would get red hot so the daily driving aspect of that wasnt real great but it sure did spool up quick and you can expect to spool up even quicker.
