Please bear with my ignorance in terminology. But I found a website that was linked in another post that shows the part that needs to be replaced
toyota Supra pictures heater issue If you look at the second photo from the top, it is the piece that has the arrow draw on it, with an inlet outlet for the coolant. Basically, the inlet piece snapped. I wanted to know what this piece is called and I can bypass it until I can find a replacement. Any help is appreciated. Thanks