I bought this one here from classic industries:
http://www.classicindustries.com/mopar/parts/md2268.html
I just got it installed last weekend, first problem I had was it leaked from the copper gasket on the top hex portion. I unscrewed it and found a perpendicular nick in it. Instead of returning it I found a replacement metal gasket and installed it. My brake light stays on now and I can't lock up the brakes, may be the valve, may be other issues.