I bought a B&B stock replacement clutch for my 69 340 Dart last summer from Rockauto and I had problems with it right out of the box. The pressure plate was set to low when assembled. The pressure plate fingers ended up hitting the damper springs in the clutch disc when the clutch pedal was pushed to the floor. It made one hell of a grinding noise.
I had to pull the whole assembly back out and return it for a refund.
I ended up buying B&B Ram "Street" Clutch #88766 from Summit Racing which worked out fine for me.
The catalog picture on Summit's web site shows a diaphragm pressure plate, but it is actually a B&B pressure plate.