I thought there were 2 different rudder config's on these boats- 1 had O-rings that wear out and the other had wax rope packing that wears out. Mine has a little side to side slop in it with 300 hours also. About 1/8 inch play measured at the lowest point on the rudder from the hull. it still tracks good though. I also thought the skidim rudders were not a direct replacement but require some fabrication and glass work from what I have read. I could be wrong, though.
-Rich
1990 Supra Mariah/351 PCM 1:23-1 PCM