They appear to be the same vintage as the new-in-box set I had Dwayne prep for me in 2000. In addition to the porting, they also required new valve guides, and some significant chamber work & milling to equalize & reduce the chamber volumes. In addition, the rocker arm pedestal / valve stem geometry was jacked up until I found a brand of rockers & shaft pedestal shim stack / lash cap combination that corrected the geometry.

The end product performed very well, but the cost in money & time to get to that point was way past what I'd expected when I purchased the bare castings.

That's why Dwayne emphasized "really cheap" in his caveats for them.