I will assume that you have a stock 67 trany with bignut reduction. Could be worn out or broken fulcrum plates. Jack up one rear wheel at a time and check for slop and noises by rotating each wheel back n forth with the trans in first or reverse. Also on the road try shifting during a curve in both directions any difference? Also check the front trany mount up by the nosecone. A worn out nosecone will leak onto the mount turning it into liquid rubber the nose cone then bounces off the torsion spring housing.
Chris
Help!
>
> My 67 Bus makes a slight "knocking" sound driving around town. After I let
> go of the clutch and press the gas to go, there is a knock or knock-knock
> that comes from the engine. It's not as severe as the sound of an engine
> with a broken rod ....