does anyone know the difference in pitman arms??

The big block arm is about 3/4" longer to better clear the oil pan
I would agree, they are different shape, I had ordered a pitman arm from classic and when it arrived the shaft hole was 1.25 " while the pitman arm I removed from my steering box is 1 1/8" and its for a big block car. I may have a 67 pitman arm as opposed to a 68'?