Yah flm doesn't really deal with people first hand. Emailing will be the best way to contact them. I understand, when building mine o had packages after packages. Its was exciting and I love the truck.

When you shim the diff, the objective is to eliminate all play out of the diff. That's play with the pinion and spur (pinion moving g back and fourth). Then play with the diff cup (side to side in the housing) but also this sets your mesh between the too as well.