EGR Valve

[84LX89GT]

If you're dead set on removing it, plug the vacuum line going to it and make sure that the pintle is seated against the EGR housing inside (so you're not flowing EGR all the time).

Why is it shot? A common problem is for EGR valves to get coated in carbon and stick in one position. If you take off the EGR valve and tap the pintle against a table or something hard to break the carbon loose, then use carburetor cleaner (let soak for 1/2 hour or so) and clean it out, most of the time you'll fix it. If the vacuum diaphragm has failed, then there's nothing you can do to fix it.

By disabling EGR you'll probably (if anything) have a part throttle pinging concern since the EGR is there to cool down the combustion chamber while it's running lean at part throttle because of the carburetor's stock jetting (mustangs got fuel injected 2.3L in '87 didn't they ).

You could try and disable the valve, and if nothing happens, then no harm done.