I've been researching the 944 016 for awhile now. I just finished comparing parts from all of the Porsche 016 transaxles from the Porsche PET. Quaife offers a LSD for 1986 and newer transaxles. Since all of the 016 Porsche transaxles use the same differential case (from the 088 4 spd used on 76-78 924's to the last 944 including the turbo), this LSD will fit all 016 Porsche transaxles. The case part number for the Porsche non LSD diff is 088.409.121B. If this part number is the same as the Audi, it eliminated any question. (although the 944 LSD has already been used in the Audi 016) The side bearings are the same in the Audi 016 too. I think that it is sad that Quaife hasn't figured this out. They could be selling these for early 944's. The drive flanges are all the same except that the S/S2/turbo use a slightly larger cv joint diameter. (splined part is the same)
Incidently, Porsche calls the transaxle used on the 944S; S2 and turbo 083. It's still basically the same, it just has some strengthened parts. The pinion bearing is larger due to the larger diameter of the 944 turbo and S/S2 pinion gear. The 944S & S2 transaxles also use the larger bearing. They also use a different ring & pinion. It is an 8:31 (3.875) which is much stronger than the older 9:35 (3.88), the pinion gear is larger and theirfore stronger.