The original 216 engines shipped from '37 to '40 used a domed piston and a relief area cast into the cylinder head (from the center of the bore toward the intake valve pocket - corresponding with the dome on the piston). From '41 on flat top pistons were fitted and the head was simply milled flat with round recessed pocket for the intake valve. California Bill's book suggests that the earlier cylinder heads were thicker as he indicates that they could be milled as much .187" whereas the later design would only tolerate .125".
I have a couple sets of Barker high lift rockers (sold in sets of 6 for intakes only):
Inliners Post circa '04 But I am already getting .41" lift. The Barkers would extend that to .46" . . . but what would I gain for the excess wear and tear on the valve train? Given the limits of the head design I am doubting that flow is much different at .46 versus .41. I also fear that I would be close to coil-bind on the inner springs.
The head is back on and the valve train goes in soon. I will be measuring actual lifts shortly thereafter . . .
