Knock out the old races and tap in the new.
Doesn't the GSXR1000 have a hollow stem? I wouldn't be to keen on removing any metal from it as Suzuki already cut it to the bone for weight saving.
Best thing to do is to remove the 1000 stem and have a new one made to fit the 750 neck and 1000 triple.
I have a KZ650 frame with the GSXR1000 forks on it in the shed, and that's how they were installed.
KD9JUR
