This thread should help - EGR related vacuum line removal

Might not be obvious that the above thread references this thread - EGR Delete/Remove

The EGR valve used to be where now you see an oblong blocking plate just aft of where the upper radiator hose attaches to the engine.

If you're lazy to block the other end, slip a blocking plate between the EGR valve and manifold but leave the EGR valve in place.

Sixto
87 300D