Just bought some longer wheel studs (Cortina hubs)from ralley design. Just knocked the old ones out and it seems there are 36 splines where the stud goes through the hub. The replacement have 31. Is 36 the norm for the Cortina hub.

don't worry about it - the splines make their own way into the hole in the hub. There are no splines machined into the hub.

Just knock em in or pull em in with the wheel nuts

I agree with Mooky,the only thing I would add is that they must me a tight interference fit.

Cheers

Rich