I know I have beat this topic to death but now is the time to put a motor together for my Challenger. I have a running 400 engine, I bought some mildly worked 915 heads with 181/214 valves. I was set on using skb240 pistons in whatever overbore it needs(to be determined) but have heard stuff I did not like about them losing their tops or shattering so I want to pick some brains and figure out a good forged piston to run with closed chamber heads and magnum exhaust manifolds. the car has air con too. I am aiming for somewhere around 9.5 to anywhere just below 10. Any help would be greatly appreciated.