SAVAGE XS Heavy Duty Gear Shaft for the WR8, and the Savage XS and Bullet trucks! These Heavy Duty parts will reduce drivetrain wear and extend service intervals. Other Heavy Duty Parts also available: HPI109920 – HD CENTER DRIVE SHAFT 5X26.5MM HPI109921 – HD AXLE 5X40MM HPI109922 – HD CUP JOINT 5X10X19MM HPI109923 – HD CUP JOINT 5X10X15MM HPI109924 – HD CENTER DRIVE SHAFT 5X31MM HPI109925 – HD GEAR SHAFT 5X29MM HPI109926 – DIFF SHAFT 5X23.5MM HPI indicates this will work with: Savage XS Flux GT-2XS – HPI106571 RTR WR8 3.0 Ford Fiesta Abu Dhabi – HPI106949 Bullet ST 3.0 w/ 2.4GHz – HPI107004 Bullet MT 3.0 w/ 2.4GHz – HPI107006 RTR Bullet ST Flux W/ 2.4GHz – HPI107008 Bullet MT Flux w/ 2.4GHz – HPI107010 Ken Block WR8 with Ford Fiesta H. – HPI109313 Bullet ST 3.0 – HPI110660 Bullet MT 3.0 – HPI110661 Bullet ST Flux – HPI110662 Bullet MT Flux – HPI110663 Ken Block 2013 GRC WR8 Flux – HPI112715 KEN BLOCK 2013 GRC WR8 3.0 – HPI112868 WR8 FLUX KEN BLOCK 2014 FORD FIESTA – HPI114183 WR8 3.0 KEN BLOCK FORD FIESTA ST – HPI114187 Savage XS Flux Ford F-Series SVT – HPI115125 WR8 Flux Ken Block 2015 Ford Fiesta – HPI115383 WR8 3.0 Ken Block 2015 Ford Fiesta – HPI115458 SAVAGE XS FLUX VGJR – HPI115967 WR8 FLUX KEN BLOCK GYMKHANA FORD – HPI120036 WR8 3.0 KEN BLOCK GYMKHANA FORD – HPI120037 Savage XS Flux Chevy El Camino – HPI120093