knocking noise?????

[therock]

well now that the brand new engine is in the car and gven me more than enough probs it is knocking now we thought it might have been the flywheel or the torque converter so we pulled the tranny this weekend and everything looked good. The car only knocks when you start it up and when your just about to shift so could it maybe be a spun bearing or a rod bolt??? any hep would be great thanks