Decent water pump for SMC?

[James Lamb]

Long story short, needed to replace water pump on my 89 Burb with 350. Parts place I usually have very good experience with (not a big box store) sold me a GMB water pump. I had never heard of them. Put it on the truck, it immediately started leaking out of an access plate on the back of the pump. I mean, within 45 seconds if even that long. It wasn't even under pressure. I still had the radiator cap off letting bubbles of air out and topping off with fluid.

Anyone have recommendations on one that is decent? Assuming the dealer even still carries one for that year is this a dealer part now? I've used non-oem pumps for years, but I guess now that things are made in China maybe that does not work anymore.