They are over $5,000. As for the exhaust, I've had friends have good luck with the '68-'69 B-body HP manifolds in A-bodies with 440s and power steering. They used cop boxes since the return line came out at a 90° angle instead of the regular 45°. Can't remember how close it was to the driver's manifold and if that is a requirement. They used the DC K-frame method, and in doing so, the motor should be mocked up first to make sure everything fits. If using the measurements for the DC copy, there may be interference. Read these: