[blykins]

The "4" on the front of the head next to the valve cover means it's a 4V head.

From what I've seen here on the dyno with factory heads and milder setups, you can easily make 400-420 hp.

You can also change the cam if you want to something thumpy.

If you do decide to change to a Windsor, the motor mounts and drivetrain will bolt right back up. Headers will need to change.