Boiling over of the battery is, from my experience, a voltage problem. Had that with an old Ford van, of course, it was the old style generator and the regulator was an external job. I used to get my alternators and generators from a local rebuilder over near the ship channel bridge, but don't know if they are still there. They would either take yours and rebuild or, if they had that model, rebuild it for you. There may be some of those kind of places around Houston.