I'm looking for insight on a problem I'm having with a '67 straight 6 automatic. I just had the head rebuilt. Now that it's back together, there's a new noise. It's like a metallic clanking periodically. It happens more when the throttle is opened just above idle. Another problem I'm having is a rough idle when the car is in gear. It's just fine in neutral and park. In drive, the idle gets quite rough and the motor starts to bounce around. There are no vacuum leaks. The motor mounts and tranny mount are new. The timing is correct, and the problem happens at any timing.