I'd find something better to waste my money on,I have a set and they are worth crap IMO.Genos garages has a stud kit or if I was you I would just but some nice shinny bolts if that's what your looking for.
The size is M10x1.5 about 45mm long if you don't use spacers. If you do, add that length. You can get them from Cummins, they are the same as the manifold to turbo studs.