EM plates

[voucht]

Hi,
For a Roadster Sierra donor, SOHC Pinto engine, is it compulsory to make the engine mount plate assembly as the book ("box" made of plates EM1-2-3-4)? I saw pictures of Roadsters with only one plate (looks like EM3) welded directly on top of BR1-BR8/BR2-BR9. First I thought it was only for the MX5 based Roadsters, but I also see pictures of this set up with a Pinto. Of course, I understand it allows to place the engine lower and to lower the centre of gravity, but isn't there any sump clearance problem ?
Thank you for giving me your mind or sharing your experiences about that.
Sylvain