Turbo identification and advice anyone?

[PainTrain]

I'm looking to fit this to my R33 GTST at some point, it was recommended to me by my tuner (now out of business).











I believe it is a Garrett T70 with a T4 flange, however all after market exhaust manifolds for my car are T3. Would fitting be a simple matter of cutting of the T3 flange and replacing it with a T4, or is there more to it than that?

Cheers