You will not find a new pressure plate (9 bolt) at NAPA or any other FLAPS.
I have a 1950 3600 (3/4 ton) with the same set up. I believe I have an extra pressure plate. Also, make sure the pressure plate tabs that hold it together are not loose. I fought a noise for 6 months. Went through 2 T/O bearings and several other things only to find out it was the pressure plate problem (loose tabs) that was causing my noise with the clutch engaged.
