1966 Mustang 3 spd to a 4spd

Bob A · 03-23-2008

I have a 66 mustang 289 with a 3 speed transmission & thinking about swaping it out with a 4 speed top loader. Will there be any benifet for the final drive gear. Does any one know what the the a 3spd vs a 4spd toploader final gears are. Will I see my RPM's drop when driving on the highway???

andrewmp6 · 03-23-2008

If you want lower rpms on the highway look in to a t5 swap.

Veronica · 03-23-2008

Hello.

The final gear on both of them is 1:1 . Third gear is the one that's missing on a three speed, not fourth.

shagadoodle · 03-23-2008

ya t5 swap will be the one u want to lower rpm

Bob A · 03-24-2008

As usual THANKS!!!! I think I'm sticking with the 3spd