Small block heat riser pics (round type)

There's a coil (heat) spring on the weight side, and a return spring on the other. The shaft must turn freely or new bushings will need to be installed. (an expensive endeavor.) Then you have to lubricate it with a graphite spray ever so often. My heat riser on my '72 340 had to be replaced back in '85. My advice….Disregard the whole thing. Google it, and there should be pix somewhere.