70 340 Dart Driver

When you where breaking in the cam did you have gear oil in the gear box?
Well, after swapping 2 wires in the firing order I started my engine. After breaking the cam in I adjust the idLe down to 850 or so. Now I hear a loud clunk noise that I'm pretty sure is coming from the 4 speed trans. I only hear it at idle I hoping it's the clutch fork not being connected to the z-bar.