It didn't really changed to cylinder heads, just helps to expain how the choice of pistons came around. Pistons alone do not an engine make, and without matching up the right components with any piston you could come up with major disappointment. Many on here will advise you to not use 360 heads on a 318 because of loss of compression, but we were just simply helping you understand that with the right combination of parts you can still obtain a CR that is considerably better than stock.
