Tamiya 42182 TRF416 Chassis Upgrade set
 

Tamiya 42182 416x Chassis upgrade kit, contains all the parts to convert your 416 to as near as a 417 and Lipo compatible.

Used, but in good condition.

2.25mm carbon fiber lower deck x1
2.0mm carbon fiber upper deck x1
Aluminum spacer x2
3mm aluminum lock nut x2
Battery mount (3 types)
Aluminum battery post x2
Aluminum servo mount x1

Very difficult to get hold of now.
£60 includes posting in UK