good luck drilling where you need to.... best bet is to buy new and know that it will not scatter ... and scatter you.
Welding will not hold at those rpms ...side step the clutch a few times and the welds will start to crack. Its not a matter of will it hold... its a matter of .. when will it blow.
But if you feel like trying... Go for it... but do not come back here complaining that you have no legs.