my previous sr20det uses 850cc injectors, walbro fuel pump, tomei fpr, garrett hybrid turbo, haltech e6x, tial wastegate, blitz intercooler, custom oil cooler, 1.5mm metal gasket and apex'i avcr..
boost was set at 1.2bar and i got around 330whp.
in my opinion the set up is good for more, but needs bigger turbo. forged internals is recommended too as 350whp is roughly around 400hp at crank.. some say 400hp is at the upper limit of the stock internals.