I am not running the new aluminum pins yet and I haven't heard much discussion amongst the other team guys about them but maybe someone will chime in.

Regarding the diffs, I have also noticed that the only time my shims were concaved was when I was overflled the diff. Otherwise I have rebuilt my EB and NB diffs ten times in the last 3 months and have only had 2-3 shims concave and it was always the rear nitro which i run 3k which flows out of the bottle real fast compared to 10k so I tend to overfill by accident on NB rear diff. That said even when they did concave, the diff still operated fine.

Also, as mentioned above, just because the oil is dark doesn't mean you have a leak, the black grease you use on the outdrive and on the oring get mixed in and change clear oil to dark real fast, its inevitable. If you have a leak, you will see it all over the inside of your diff case.