[Jac Mac]

While they look the part Doug, in practise they are a pain in the butt, If the studs are not dead straight & or the heads dont have the stud holes machined exactly as per the original Ford drilling/tapping accuracy you can get into a problem when tightening down the 'Acorn' nuts that fit on the stud tops where they tend to bend or deflect the stud slightly as they are tightened and in doing so the carefully set valve lash alters in the process. Probably not a big deal on a hydraulic cam setup, but in a solid lifter deal it can be a problem. Todays bolt on roller rocker setups are probably a better deal and you could just glue the acorn nuts in place if you really want those covers.