I have a customer with the Chevy 400 and his leaked from new and they had no problem sending him another one.
I just bought new pulleys and an alternator bracket and the water pump pulley didn't quite line up I had to use some washers to shim it. Also the hole was a little too tight going over the water pump and I called them on it and they were just about willing to send me another one but suggested I Emery cloth the water pump a little bit. It took her just a little bit more than that on the water pump but it fit on. Again they seem quite willing to send me a new one had I had any more issues. I guess what I'm trying to say is their customer service seemed pretty good... Also I really like the alternator bracket as opposed to the factory stuff..
