don't thing you could push a 318 bore to 4.07 without it being a hot running motor , how thick are the cylinder
walls ? did you do a sonic test on the cylinders walls ? if it can go that , i'm thinking on some 340+.04 pistons in stock , a 318 block lower end in stock . same crank stroke , same length rod , same pin size . todays gas would be shaving the tops on the pistons . well whats anybody think ?