by the looks of the egr spacer it is the same as my edelbrock mustang unit,
before you pull the old one off just check the throttle cable mounting point,
if it is the same as mine it wont have the bolts for the "backwards facing" aussie manifold.
if this is the case mark it out thenand drilltap two 3/8 unc threads through the main body & through the water passage and just into the inner section by a couple of mm ,the depth will depend on the bore thickness.
the reason I drilled into the centre was the bolts kept coming loose and needed to be located for extra rigidness, the rest is pretty simple you can make a propper spacer, use washers or have it adjustable by using a nut on the inside then a flat washer and the same on the other side of the bracket
You MUST use a thread sealant when doing this
cheers kenny