Just to add a little more info to this thread, you do have to be a bit careful if you are using the Beta wheel spacers with original Cromadora wheels, I was not happy with how far the wheel bolts screwed into the hub if they were being fitted. Bolt manufacturers stated at least 8 full rotations to be properly secure and I found that the bolts on my car with spacers they were doing four/five at best. As they are quite an important part to keep on the car I opted for longer wheel bolts, but did have to turn them down 5mm because I could not buy the right length from the start and the next size up (45mm I think) went in too far and locked up the whole hub.
If you want spacers and need exact measurements just shout
