5.7/6.1 hemi temp

So out of curiosity, how low is too low for temps? Right now mine runs stone cold humming down the road, something like 170 most of the time. Not sure if my thermostat is a 160 or 180 though, would have to pull it and double check. It seems like I might have a little more crankcase blowby than I'd like looking at my air filter and PCV connection, wondering if this might have something to do with it.

For those that don't know, the thermostat is the same physical size as a plain small block one. That's how I have such a low temp one in there. Had the 318 out and didn't really want a 203 stat in the car so I figured I could check the sizes for fun. Sure enough, the stats are the same size, so I went ahead and swapped them. Better than paying the $40 or whatever for the "performance" low temp Hemi one in the parts book.