Speedometer gear

Thanks Brain. It's just the short gear of the newer trannys tend not to be thgought of when people resond with what they think is the correct part number. I noticed right away that there is is; 2838939 supercedes to 52068061 But doesn't mention if it for new or older style gear.

The chart there states;

1966-1989 727 & 904 Automatics Transmissions

Can there be some mistake in this?

Can I convert the old style to a new style and what about speedometer hook up.

This is the dilema. For this car (Magnum) and my Duster.

Also, side thought, does anyone know what the back of the Autometer/MP speedometers do for a cable and what it takes to hook one up?

Thaks fellas.