My CFE w8's had a sleeve where the head stud area was broken through. They also used a 7/16 head stud instead of the 1/2". Was told the sleeve was to strengthen the head so the head stud when torqued down would not crack the head. Probaly less chance of cracking the head with the less torque the 7/16 bolts require to stretch the stud.

Leon

Career best 8.02 @ 169 at 3050# and 10" tires small block power.