First off this diff is a very nice looking piece. Mine must be a newer version because it was dark grey hard anodized and had the new "F" logo.

However, I did experience a few fitment issues. First off the center pin for the 2 spider gears did not fit in the diff case. My stock pin measured out at 9.9mm and the area inside the diff cup was 9.7mm. Easy fix for me but for those with less tools or experience could be a deal breaker. I also had trouble fitting the motor mount bearing onto the outside of the cup. It is basically a press fit and requires a lot of effort to install the bearing, I fear I will ruin the diff cup if I ever need to remove that bearing.

All in all this part has issues but they can be overcome unlike other options.

This aluminum center was well worth the wait. It's a direct drop in with not a leak in sight. Put 6x5000mah 45c packs for about 1 hour on the track and not even a sweat for this diff. I'm glad I bought 2, keep up the good work FLM!