Hi all

My sti 7 is running a very respectable figure of 410bhp and 447 llbs torque, on a standard 2.5 lump and sti heads, (obviously loads of other bits but cant be bothered to bore )
Anyway to get more power out the beast ive been told the way to go is uprating the internals and bigger turbo, currently an aps sr55,
Can anybody suggest what would be the best way to achieve bigger bhp and what parts would be best to use?

Thanks