Hmmmm - I'm aware of an AT71ELC (and think there also was an AT70LC or AT71LC), but just like with the CD of the AT92ECD, the extra letters in the suffix in these cases don't really belong to the cartridge designation, but rather indicate a certain kind of packaging - which is why I usually put these in backets (AT71E(LC), AT92E(CD), AT120E(/T)...), and of course there was an AT70L (with pretty high tracking force/low compliance, light grey needle). however, I'm not aware of an AT73LC - but LPGear appears to have heard of it and offers the ATN72E as replacement needle for it.
Anyway, tracking force for your ATN71E would rather be 2 g (+/- 0.5 g). And tracking force always is determined by the needle type, not by the body.
Greetings from Munich!
Manfred / lini