[rotorwrench]

The C6 and MX were both used in FE set ups in 1967. The MX Cruise-O-Matic was used in the lighter duty 390 2V applications and the C6 was used in the 390 4V and larger engine applications for Mercury cars. There were floor shift and column shift versions but there was likely only small differences. The trans model number should be in the PGA (floor shift) or PGB (column shift) series.