Dave.. the original poster said 350bhp..

Why don't you compare the T34 compressor map to the GT35 ones you display above.. ?

Also, you must take into consideration the fact that you're not going to be achieving 350bhp @ 1 bar to stay in the peak efficiency area of the GT35 map.. Once you actually pipe up to the 1.6 bar (or thereabouts) that you need (at a reasonable efficiency) then you're starting to wander a little bit..

Sure, the GT35 looks like a nice compressor.. the smaller trim is more suited to 350bhp.. not sure how that indentation in the surge line will actually affect things IN the car.. ya never know until you try..