161 is 1 candlepower and has a blue insulator.
194 is 2 candlepower and has a white or clear insulator
168 is 3 candlepower and has a brown/gray insulator
I'm not aware of a direct translation to LEDs, despite what the LED sellers will tell you.
I also can't relate what kind of life to expect from the different ratings. But it is interesting to note that GM was very specific about which of them went where. i.e. the 4WD light is a 161 because you don't need that indicator glaring at you, but most of the rest of the dash lights are 194s, and the marker lamps are supposed to be 168s.
A lot of thought went in to it, but considering that during most of their lives these trucks had bulbs replaced with anything that would fit it seems reasonable that the LED sellers can equate all the different bulbs to one and most people will never notice.