i have been curious about something else. 1979 911sc differential
 

Are these posi traction, open dif, or limited slips? It quiote feels like posi at times, l/s at other times? Lemme know. thx

if its a factory limited slip it will have a 12 stamped somewhere in the code on the bottom of the tranny. or you can just jack it up and spin the wheels to check

I am wondering what is more common? anyone else?

Most of them are open diffs, but all 911's, compared to standard rear wheel drive cars with front engines, like a camaro, pickup, or chevelle actually "feel" like limited slips. They "hook up" with far more efficiently than a front engine/rear drive vehicle.

I'm not an engineer, but my humble shade tree mechanic opinion is that with some 60% of the weight over the drive wheels, a 911 by nature has a great deal more traction than a front engine rear wheel drive vehicle.

angela (shade tree...)