I reached out to the manufacturer, Bulldog Winch, who was able to supply the installation instructions for the Bulldog Winch Custom-Fit Steel ATV Winch Mount # BDW15116.
These instructions will come with the winch mount, and said the 4-bolt pattern was 4.9" x 3” (124 x 76mm), and 2-bolt on the center line of fairlead/drum of 3.15” (80mm). For a winch to use with the Winch Mount # BDW15116 you can use the Bulldog Winch Powersports Series ATV Winch - 3,000 lbs # BDW15002 or 2,000 lbs # BDW15001. view full answer...
The Bulldog ATV Snowplow Winch # BDW15021 can be mounted directly to the snowplow provided there is a suitable place to mount it. You can refer to the linked image that shows how this winch can be installed on a plow frame that has the necessary mounting point. view full answer...