when im driveing in my 65 the stock speedometer it has gets to about 10 MPH and any faster it will start doing this strange clicking noice and it will "bounce" up to a much higher speed and back down to the speed im going at, what can cause something like that?

 

Either the cable is going bad (most likely) or the speedo itself is going bad (less likely, but it happens). Disconnect the speedo cable from the back of the speedo and you'll be able to pull out the cable...but it's likely to be in two pieces if it's in too bad of shape. New ones are as close as your local auto store.

 

Mine does the same thing, well actually it just sit at like 190mph. This is after replacing the cable and housing too and I am on my second speedometer. I am going to lube up the new cable with some lithium grease and see if that works.

 

If it's wound fully clockwise, that's a big problem. If it's going counter-clockwise, you have a problem with the gears being cut the wrong direction.