the spool wont work with the 3mm cups and the 3mm is what you want. I had the same problem with my 3.3 now I have the 3mm cups and a picco .26max in my truck and have had no problems. The stock spiders work fine but you will need to either modify the ring gear to accept a 3mm screw or buy one. I think RRP make a ring gear for a 3mm screw.
And shiming the diff helps as well. But Once again get the 3mm not the 2mm, 2mm is the same as stock and you will have the same problem.