Question on axle codes.  I have either a 67 or 68 rear axle and trying to determine what gear is inside.  The tag has the following.  

WCZ  V1  179
8DD  930

I have spent 2 years doing a complete 1993 5.0 efi swap in a 67 convertible and now the speedo is not reading correctly.  I am assuming the the gears in the rear end are different from the 93 causing the problem

Any help would be appreciated.

thanks