Thanks Jon.
Weird how all the parts places (even Motorsportauto), lists different part numbers for the front seal R200's broken down in 74-89 z/zx, 90zx, early 91 zx and late 91-96 zx.
The side seals though are all listed the same thru all the years. I guess different pinion flanges were used but I mic'd my 2 I have from both my R200's and they both seem to be the same dia and everything else identical, altho different 4 bolt patterns on them (one is a round bolt flange off my old Z R200 I need to reuse to match driveshaft and the other is the rectangle 4 bolt flange off R31 Skyline 4.38 LSD im swapping in). To be safe ill just get the early Z seal for the old R200 flange.