Your onto something. Well it does offer a "cushion" of 20 Deg before "boil over". Not that a big a thing, must be something more than that to it! OK, how 'bout lower engine temp keeps incoming air charge (to carb) cooler and more dense, offering better performance? Well,,,route your air cleaner so it gets cold air anyway and you still haven't gained much with a 160. Lets see........ The motor requires a richer mixture at a lower engine temp, thats for SURE. Wait, is that a benefit? Don't think so!
Oil stays cooler? Hmmm,,,not sure thats a "good thing", more sludge build up becomes possible at lower engine temps.
All this ASSUMES of course that the engine temp will actually FOLLOW the t-stat temp! It could, regardless of your fan t-stat setpoint. At "speed" you may not even need the fan at all. When you DO need the fan, the temp "curve" will follow the fan t-stat setting NOT the engine t-stat setting. So make you fan t-stat ALSO 160 if that's what you want!
I got fuel injection, I'm going with 195 myself. I think HOTTER is BETTER!
Ernie