The diff gear is the same material as our TC3/ B44 gears and B4 idler gear. All new B4 diff gears are made out of this as well. This material has no coloring and is the most durable we've found. The original photo gear was black because that's all we had at the time.

The T4 CVDs will work. Others:

1283 FT T4 Ti Turnbuckle Set
1406 FT Ti Turnbuckle, 2.00” (blue)
1408 FT Ti Turnbuckle, 2.65” (blue)
1409 FT Ti Turnbuckle, 1” (sway bar) (blue)
1417 FT Ti Turnbuckle, 2.80” (blue)
1585 FT B4 Aluminum Trailing Axle
1595 FT Chassis Lead Weights, 1/4 oz.
1598 FT Blue Aluminum Shock Caps, (blue) see also #6439
1654 FT Solid Axle Pins
1734 FT Blue Body Clip, 4 long, 6 short
1735 FT Blue Body Clip, long
1736 FT Blue Body Clip, short
1770 FT Milled Aluminum Motor Plate, (blue)
1777 Blue Aluminum Shock Ball Ends with Eyelets
1778 FT Milled Aluminum Motor Plate, (black)
1779 FT Servo Mounts, blue aluminum
1780 FT Blue Aluminum Threaded Shock Bushings
1781 FT Rear Shock Bushing (short)
3971 Steering Rack Bearings
6416 Gold Shock Shaft, 1.32” stroke
6417 Gold Shock Shaft, 1.02” stroke
6439 FT Blue Aluminum Shock Caps, (blue) see also #1598
6906 Ball Bearing, PTFE Sealed 3/16 x 3/8”
6937 FT 4-40 Aluminum Locknuts (blue)
6943 FT 8-32 Aluminum Locknuts (blue)
7412 Rear Threaded Shock Body, 1.39”
7414 Front Threaded Shock Body, 1.02”
7416 FT Threaded Shock Collar & O-Rings
7447 T4 Front A-Arm, Carbon
7449 T4 Rear A-Arm, Carbon
7922 GT2 Caster Block 30 deg, (left & right)
9565 B4 / T4 Chassis Brace, Hinge Pin Brace, Carbon
9567 B4 / T4 Top Plate, Carbon
9577 B4 / T4 Steering Block, Inline (left & right) (req. #9623)
9592 B4 / T4 Caster Block 20 deg, (left & right)
9600b FT B4 / T4 Aluminum Motor Plate (blue)
9608 RR Axle Wheel Spacer (silver)
9610b B4 / T4 Blue Servo Saver Bolt
9633 FT T4 Front Threaded Shock Kit, 1.02”
9634 FT T4 Rear Threaded Shock kit, 1.39”
9635 B4 / T4 Sway Bar Kit. Includes color coded bars,
soft (black), med (silver), hard (gold)
9665 FT B4 / T4 Aluminum Hinge Pin Brace V2