Hey guys wondering if anyone can help here. Two questions. I was looking for the drain on my radiator for a 99 2 door 4 wheel drive Tahoe. Anybody know where it's at? My hose clamp at the water pump is leaking. Second as I was searching I found a plug zip tied. Way down low at the radiator on the driver side. It had a cap on it and I'm wondering if this was a Factory block heater? I bought the truck new and I don't remember anything on the window sticker about a block heater and it would be odd to have one on a gas engine. Anyone know what this is?