brucep

I've had to replaced the speedo cable in thew car because the head end snapped off of one in there that was in a grey case. The black case and cable I have in there now is much longer than the previous one. I'm wondering what the correct length is. LI Corvette lists two for 66, one for 4-speeds and one for 4 speeds and autos. I'm not sure which of the two I have in there now, but that's where I got it. My concern is I get some needle bounce under 30 mph which never happened with the other cable. I believe bounce like this tends to be caused by cable binding in the case. It's well lubed too btw.
Thanks.

JohnZ

There are only two speedo cables - a short one for 3-speed and Powerglide, and a long one for the Muncie 4-speed; the 4-speed cable is about twice as long as the 3-speed cable, and the short cable won't even connect to a 4-speed. The cable routing and clipping is shown in your A.I.M., in section M20.