I know this topic has come up many, many times, but here is what I would buy for replacement parts for a new 410.3 owner. I have had mine for almost 1.5 years now.
PARTS TO BUY WITH YOUR ORIGINAL KIT FOR BACKUP/PERFORMANCE
Aluminum A block (Will break yours soon)
Tekno Aluminum Servo Horn (Plastic will not last)
Front A-Arms (Will break after a while, especially cold weather)
Hings Pins (Will bend often)
44T Spur Gear
PARTS YOU WILL WANT TO ACQUIRE SOON
Aluminum C Block
Carbon Fiber Rear Shock Tower (mine keep bending)
Hub bearings
Differential housing bearings
Air Guards
Shock Tower body mount (have seen them break often)
LONG TERM WEAR ITEMS
Front Bumper assembly
Differential outdrives
Center tapered aluminum drive shaft
CVD assemblies and hardware
Plastic Rear Hubs (Mine wore out after 1 year)
Differential center outdrive bearings
Just my .02. I'm sure I'm missing stuff.
Mark