Overdrive Cable Clamp on a Shoebox woodie

[wga]

Ref 49 wagon
Attaching the OD cable with an Addell clamp, which is OK, there is some
movement of the cable inside the clamp. Using the side of the transmission
as a mounting point. Should I be using the smooth end of the cable?

What is the preferred method of mounting and the type of clamp?
Side of the transmission

Any suggestions are welcomed.

thanks