'65 chevy c10 - bad vibrations! things to check?

[Woogeroo]

Howdy folks.

'65 c10, chevy, long wheel base, stepside, 350 engine block, th350 3 speed auto transmission, coil spring rear with the arms...

My '65 c10 has started a new thing where there is a vibration when I go from being stopped, to when I begin accelerating... then it goes away once I get up around 20 mph or more.

The tranny fluid is good... and the same color translucent red... not black. Of course, it could very well be tranny issue, but I have no idea.

Any ideas on basic things to check before I take it to a shop?

I'm planning on taking the rear wheels off and checking out the brakes, as I had a issue earlier this year with the right rear brake shoes sticking and rubbing down to nothing.

Anything else to check?

thanks peoples...

-W