Just got my kit bashed sw10 today, I've been dying to get one forever but too cheap to get brass. Gotta seam or two to fix then it's off to the paint booth. May go tux, sublettered CTC or lop&g, may go horse head, toyed with the mighty K&IT even, still unsure, gonna have some gm&o and IC power for interchange but doubt I'll paint it for them. It's a good day at the Wells roundhouse.
Hmmmm... a butthead with Dynamic brakes??
I wanna say it was a cooling thing due to the troublesome old belt driven fans, I know they were upgraded to 645's, but maybe dynamic was involved too, I never really saw any specs on the hammerheads.