They are confusing as s**t lol
Twason, I think thats right, knew it was one or the other.
So a 'High performance slip resistant' tag, indicates a 4pin ls centre.
Can still get the 2pin centres (no idea what they came in? EA-EBI? And BAs lol), which, in theory, should just say 'slip resistant'
All academic anyway, there doesnt appear to be a way to pick a 28spline diff without cracking it open.