On my 89 302 van, the EVR is not supposed to hald a vacuum. It passes air all the time and modulates the amount of vacuum that goes to the EGR valve. It even has a filter in it because air goes to the intake through it at all times. So if yours is of a similar design, it may be ok.
Make sure it is not applying vacuum to the EGR valve at idle and see if it does apply vacuum when you raise rpm to 2000 or so. If it does that, it's probably ok.
Hope this helps.