[JCA1972]

I have a 71 c-10, I got it on the road last September and I noticed that it makes a whining noice when going between 30 and 50 mph. Kind of like WHaaaaaaaa. when I slow down it quits making the noise. I have changed out the transmission, u-joints and carrier bearing on the drive shaft, and it still makes the noise. I took it to a rear end place and they said that they didn't think it was the rear end and they couldn't tell me what it was. I'm hoping that some of you C-10 pros might have the answer. Thanks in advance.