Re: Brakes Feel Weird
Two words - vacuum leak. Your 87 I'm sure has power brakes and the booster works on engine vacuum. Lots of hose there to leak and they get brittle over time. Not too bad to fix but if the booster itself lost it's seal (not normaly the problem but it can get to that) then you have too spend some $$. Not a fortune but it can still smart. Of course no brakes hurts more.
This of course is one posibility but, you did mention all the other parts you checked and I think you've got it narrowed down pretty good. Hoses are cheap too. Probably worth replacing anyway and you'll solve more than one problem at a time. Vacuum leaks are notorius for poor engine performance as well.
Tread lightly and stop to smell the roses - Traveler