I just received all my parts and built my GD2 with ARC internals thanks to Kody's part numbers post a while back. FYI for those that didn't see it before you ask why I used ARC parts - the Xray parts are sold out or hard to find all 3 part numbers in stock.
Everything went together as the assembly drawing shows and is pretty smooth.
Trimmed cross down to 20.8.
After a dry assembly checking backlash I used 2 shims (ARC# R103023) behind the spider gears.
Filled it with oil, bled through the out drive and its pretty smooth.
Ill let you know how it runs after this weekend.