Rega P3 with BENZ ACE - Spacer required?

I recently ordered a Benz Ace cartridge for the Rega P3. Before it arrives I would like to have all tools I may need ready so I can start using this thing as soon as possible. I was just wondering what size spacer I would need. I am currently using the Goldring 1042 and required a 2mm spacer, will I need a 4mm?
I've used a 4mm Rega ring with an RB300 arm and a Benz cartridge with good results. Since there's no VTA adjustment on the Rega arm, the spacer raises the arm to a good height to compensate for the thicker vinyl a lot of us buy nowadays.