from what i have gleaned over my years of tinkering with turbos,
you WILL (if I did not make that claer) WILL need a carbon front seal if you want your motor to run for more than a few seconds, before fouling the plus with oil.

Iv found they index turbo balancing off the shaft and exhaust wheel , and only take material off the turbine wheel.
So I just line up the index marks on the shaft and wheel and bob should be your uncle.
Iv done this a few times, once re-building a std. tarbin, and a couple of times with "hybrid" style turbos, (one compressor on another turbine)
they all seem to run fine with no balance problems.
If your running a draw thru set-up, Id recomend getting it rebuilt with a carbon seal. (if your running a draw thru set-up you WILL need a carbon seal)

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