​I put a fishing specialties pole mount on mine. I took this from their website. Maybe it will help you. Here is a link to some pictures on their site. Installed Mounts - Fishing Specialties Inc
Typically a 48 inch downrod is more than sufficent for a DeepV boat and a 36 inch downrod is fine for most Skeeter, Nitro Z or RangerZ style boats.