Generac Transfer Switch Wiring

diesel_farmer

Installing a Generac 17kw with EZ Switch. The wire that came with the switch is about 12 short - panel is on opposite side of house from switch. It came with #6 wire and I'm thinking of swapping it out and using #4 wire from the panel to the switch. OR, could I splice the #6 wire into a box and run #6 the extra 12' length to the switch? Thanks.

VA master elect

Is it the 100A subpanel with the 30' flexible stalk attached?
If so, I've had to junction these before because they were too short...stick with the #6. Changing this would probably void your warranty with generac.