Could still be the waterpump. When mine went, it heated up when revs @ 3K+. I was able to drive home at low speed and it seemed to cool ok. When I took it off, the impeller was still in one piece, but spinning on its shaft!!. Guess at low revs it still turned enough to cool but when hammer down, the shaft just spun around inside the impeller. Hope this helps.
-the wife has to drive it too!) -'89 Baby Bronc 4x4 V6, -'84 Honda Shadow
