According to the escort wrc manual you should need to modify the engine block to have the engine fitted with gpa mounts.

It says
"In order to fit them it is necessary to remove 12mm from the right hand mounting bosses of the cylinder block (axle side).

Does anyone have pictures of this modification?

It also says you should use dowelled studs and that you should counterbore the block for them to fit.
Does anyone have any pictures/explenation on this as well?