I've been told this. Any idea which rebuild kit to get?

daily driver wrote:

I've been told this. Any idea which rebuild kit to get?

The 2.77 transmission was the factory unit used in the Mustang 6-cylinder cars until the 1967 model year, when both V8's and I6's came equipped with the 3.03 three-speed transmission (the V8 cars came with the 3.03 in 65 and 66).  The best way to tell them apart, aside from size (the 2.77 is much smaller), is the number of bolts in the top cover.  The 2.77 has 4 bolts, the 3.03 has 9 bolts.  But the 3.03 was also used in pickups, mid- and full-size cars.

If there's a tag on it, you should be able to confirm what it is here.  

I've rebuilt a toploader, which is similar to the 3.03, and, as TKO said, it's not hard.  There are rebuild kits on eBay and various other places (do a browser search for rebuild kit with instructions for ford 303 transmission - you can add your tag number to the search if you have it to get even better results).  There are also several YouTube videos I saw that should help you through it if you can't find a kit that comes with good instructions or if you get stuck.

To address a couple of your other questions
Does that pattern stay with the tail shaft housing?  Assuming you mean the gear shift pattern, usually, the shifter determines the pattern.
Do the different tail housings only change the location of the shifter to accommodate for an AC?  The tailhousing does change the location of the shifter but it's usually to make it compatible with different vehicles that need the shifter in a different location.  For example, the shifter location in a full-size car would not be the same as the location in a Falcon.
Are all gearboxes and linkages the same except for gear ratios?  Linkages differ with the application and shifter mechanism/location.  I don't know the answer to the ratio question
If I swap the tail housing from the other transmission to the back up transmission will I need to make adjustments to the linkage or swap linkages on the gearbox?  Maybe.  Some tail housings are longer than others and may require an output shaft change along with the linkage change.
Or, can I put the tail housing from the first transmission on the backup transmission and it works for which ever gearbox?  If the transmissions are the same model (3.03), sure.  But, as mentioned above, you may have to change the output shaft if the tail housing is longer than the one you removed.

Hope this makes a little sense.

Last edited by John Ha (2/17/2026 7:35 AM)