anyone added an alternator?

I have a Bolens tubeframe that has been re-powered with a 13hp honda clone. I intend to use a small atv winch to lift and lower a snowplow, and I'm concerned about the charging system being able to keep up demand, I have 2 amber marker lights on the front, 2 Red on the back, and they are wired to a flasher. I also have 2 55w halogen driving lights on the front. the charging circuit on my motor puts out 3 amps, which is pretty much absorbed by all of my lights.

I'm considering adding a vehicle alternator to run off an accessory belt, a spare groove on the engine pulley. I have in mind a 75 amp ford alternator from a little ranger.

Has anyone done this? Does anyone have any ideas or constructive criticism?