I'm making some progress.
I found that the IAC from the 2.8L, wasn't closing all the way and causing a massive vacuum leak. I replaced it with the 4.3L IAC which helped tremendously but now I have other problems.
The idle seems pretty steady at about 800 rpms but surges up to 900 irregularly. The motor seems to lack power as I accelerate from 2000 to 2500 rpm as if the plugs were fuel fouled (too rich). It takes off at about 3000 rpms and runs steady.
The biggest problem is that it stalls when I come to a stop. It doesn't stall all the time, only once in a while and after it has warmed up.
Any thoughts?
Jim