Diff. ???'s

[StockSucks]

Just brain storming a little here but Im looking into a kaaz or something similar but i want change to a different gear ratio... question is what can you use? from what i can tell the 95-97 j30s look to be the closest to the stock diff. so maybe you could bolt the kaaz on to the j30 ring gear and housing.... but the q45 have a 3.54 or 3.61 ratio... what im tryin to figure out is if the center chunk like a kaaz for a 240 will work in either the j30 or q45 diffs...
Any help or positive input would be great!