Cut back blades are used where there is not a perfectly matched turbo for the job.
Has it been machined and fitted with a T34 trim wheel in a T3 compressor housing, then cut back so it sits between T3 and T34 size wise ?
If it has cut back T3 trim wheel it will not even flow as much as a std T3.
No way on earth will it flow to 350, a T34, or modded T3 as above will easily flow 350, with a .48 turbine.
A .63 turbine will be lag city, noit quite as bad with modded head depending on mods ?, but a VERY odd turbo to use with lowered CR, there is NO need to lower CR for 350bhp!!
tabetha