I have run quite a few stall converters over the years, and what I can say is don't buy the "cheap" ones. I have either had them not stall to anywhere close to what they were supposed to or trash the rest of the transmission at some point. I ran a reworked Vega converter in my drag car for quite a few years which worked good, but it finally trashed the Turbo 400 behind it. I would recommend something like a TCI. That is what is in my Chevelle now and it works great.
Jeff