could someone please help me with the positioning of the front suspension brackets

i am fitting sierra front uprights with transit draglinks, maxi ball joints and mk2 escort rack

just not sure on position of the mounts, should the two wishbones be parallel,

I have no experience with sierra uprights.
I would start from the book design, and modify according the measurement differences between the cortina upright and the sierra upright.

There are several software applications with which you can design/ modify suspension geometry. I think they can be found in earlier topics.

I would try to keep both upper and lower wishbones (almost) vertical (thus paralel) in ride height.

Pictures of a jig in my blog and photo archive.

[Edited on 20/10/08 by maartenromijn]

has no one else used sierra uprights

or is it a secret...

You may be better off asking in the chassis section of the forum rather than the Luego section.