I have almost finished the rear on my 280z with a stock R200 differential and a 2 way Kazz internals from a 240sx. My 82 turbo 280zx CV axles are not seating right when they go into the diff. Is there some sort of clearance issues because im not using an 87-89 300zx diff?

The spline count is different.

KAAZ makes 2 LSDs for the 240SX. One is the replacement for the VLSD which has a larger shaft with more splines. The other is to replace the OPEN diff, and that one should use the Z31T or S130T CV shafts with no problems so far as I'm aware.