Gears & Axles - Just installed an axle and have some questions

I've just put an LS1 rear end on my LT1 Camaro so I could enjoy the better brakes and take the time to do a gear swap.

On completion, one of the LS1 axle shafts turned out to be bent :bomb:

I swapped the bent shaft for one of the shafts out of my now spare LT1 rear end and bolted it all back up.

Now I find that the wheel studs don't stick as far through the wheel as they did before, bearing in mind this is the original LT1 shaft I was using before with the same wheel.
The other side, the LS1 shaft has more than ample stud length.

I'm using new EBC rotors for the LS1 brakes.

So my questions are - are the center sections of LS1 rotors thicker than LT1 rotors?
Is it correct that LS1 studs are slightly longer than LT1 studs, because I measured them and it appears to be the case?

Finally and most importantly, how little stud length can I safely get away with. Right now the wheel nuts are on the stud about 10mm give or take - I'm not happy about it but I'm also not happy about tearing the diff open AGAIN to release the shafts so I can replace the studs.

Thanks in advance!

The NHRA requires 1 stud diameter protrusion into a lug nut for racing. Stock studs are 12mm and you have 10mm of stud into the lug nut. You're going to have to see if you can live with that. The grip length of my studs are 1.625 long on my '94.