[BigBlocksRule]

If he spent a bunch upgrading the rotating assembly and kept the peanut port heads, it wouldn't make much sense, either. They'll make decent power and keep you from over-revving the engine, they won't flow enough air to get you in trouble.
As long as you have the heads off, I'd upgrade 'em to the 781's or 049's. Even in stock form, they'll make more power, although they'll give up a small bit of torque on the bottom end. Put an ad in craiglist, you should be able to find a set fairly cheap. As long as the valves are good, leave 'em stock size and get a good valve job, pocket port 'em and you'll be set. Advertise the heads you have as high-torque, someone with a tow rig or motor home will want 'em, that's what they're made for.