Hi Axle.
If you have the book spec rack extensions you'll find that they will need shortening by approximately 15mm each ( Rack extensions ) & give or take a coulple of mm.
On my build both front wheels were still toeing out & that was after the engine, box & all the running gear fitted ( Basicaly Car on its wheels )
My extensions had been drilled quite deep & was no problem to tap a bit more thread in there
My rack is an original Ford unit ( Escort Mk2 )
If memory serves me right : The Rally Design, alloy rack extensions are OK as is.
Perhaps Ash would confirm this
The standard Escort Mk2 rack, does not need to be shortend unless you are chasing perfection ................As Chris has said in the book " It is very close to the ideal length "