"rocks in a blender" sound in my wife's slant Valiant

I have recently been educated about the 67 small snout trans thing when I was looking for a replacement for the Valiant so I checked it. The trans in this car was correct for a 72. Big snout. So that can't be what caused the problem.

Anyway the Valiant also had a cracked exhaust manifold, so I just pulled the engine and trans and replaced it with a good running 67 slant and 67 transmission. The engine has a good quiet exhaust manifold, the trans has never been off of it and the motor drove great down the road, so it was the easier way to go.