you must remove your ECU and mail it to our Bikeman facility for the Dynojet Bench Flash Unlock service prior to tuning

True Full Exhaust System: Replaces the restrictive factory one-piece setup with a completely redesigned high-flow header and matching dual-tip exhaust

Building a high-horsepower machine requires heavy-duty support parts

When using with stock compression pistons

Awesome sound

Arctic Cat 858 High Elevation Head Mod 04-411 Category_Default Category/SLED/Polaris/IQ 700 you must remove your ECUTHIS HEAD MOD REQUIRES YOU TO SEND IN YOUR STOCK HEAD FOR EXCHANGE Need more power out of your 858 at high elevation Our head mod packs some serious power, No tuning required Pump gas friendly Arm Pulling Torque