transmission questions

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

isaac300

Member
Joined
Aug 21, 2018
Messages
7
Reaction score
0
Location
Tennessee
My Car
1973 Mach 1
Hello,

I'm sure that this question has been ask 100 times. I have a 73 Mach 1 and i'm looking to put a toploader 4 speed in the car ( if i can find one ).

Will any of the toploaders work, Or do i need to look for certain years?

 
Pretty much any 65-73 Mustang or Cougar toploader will work. There are some variations of the tailhousings, but there are shifters available for most situations. Step one is to identify the transmission by it's ID tag.

http://www.davidkeetoploaders.com/idchart1.htm

Assuming you have a 302 or 351, you'll want to stay away from the big input big block units. Other car line transmissions will work, but need to be looked at on a case by case basis.

 
Pretty much any 65-73 Mustang or Cougar toploader will work. There are some variations of the tailhousings, but there are shifters available for most situations.  Step one is to identify the transmission by it's ID tag.

http://www.davidkeetoploaders.com/idchart1.htm

Assuming you have a 302 or 351, you'll want to stay away from the big input big block units. Other car line transmissions will work, but need to be looked at on a case by case basis.
I have the 351c that i'll putting in the car. As far as the bell housing, does the toploader have its own bell housing as far as trans bolting up to the bell housing. I have a bell housing that i think that will work on the engine, But the pictures that I've seen of the toploader looks like it different bolt pattern to mount to the bell house. If that makes since.

 
Here's a bit of information I found in one my transmission files:

Bellhousings that will be used with a Toploader must measure 6 1/4" deep. If it measures 6 3/4" deep it is a truck bellhousing and should not be used.

 
Proceed with caution, lol. There are probably hundreds of combinations, why I do not know.

The site mentioned does have lots of info on them. They move the mounting points for the shifter all over the place depending the car it came in. The first toploader came in the 1964 1/2 mustang and only had a 25 spline output shaft. They only made for 90 days and was switched to a 28 spline. It also had a narrow bolt pattern where it bolted to bell housing. And yes the Falcon is different than the Mustang, moved shifter around.

They are not difficult to find but you should always open the cover and look inside. About all you can tell is general condition of the gears and syncro rings. If you see lots of shiny particles in the grease do not buy it will be a money pit. There are different length of bolts in the cover so keep track of where they go.

The pedal assembly, bell housing, flywheel, clutch and all the linkage will cost you more than the transmission. If you can find one in a crashed car might be best place and get it all. The pedal for PDB is different than non power also.

As far as I know the 3 speed pedals and linkage and bell housing are the same as 4 speed and cross member also I think cannot swear to it.

If you do not find one try Scotty Strickland in Oxford NC. Look for him on facebook. He had a trailer with a row of them in it last year. He does not sell some things has a hoard or R models, parts such.

You can get any piece you need from Dan Williams in NC google him.

They will break my X broke 3 rd. gear with stock engine in a 73.

Here is pic of the first one out of a D code 289 4-V 1964 1/2. Guy wants it for a restore but has not came up with the cash. $1,000 because they are very hard to find all good and date code correct. You for sure do not want this version the Cleveland would snap the output shaft firs time you dropped the clutch.











school poetry

 
Thanks for all the help. I've done some research on the transmission, and see where there is a millions of combinations of the toploader. The reason for swapping over is because the car has a c4, and i have a FMX, i was hoping that the car would have a c6. I was thinking it would be better money spend to go with a 4 speed since i plan on building the 351c.

 
The C4 can be built to handle a healthy 351C. You just need to source the upgrades and rebuild from a proper source. Chuck

 
Agree with Chuck, a C-4 can handle alot of juice. Check out Dynamic in Branford, CT. They know how to build a C-4.

That said, I'm a 4-speed guy. Every 71-73 Mustang I've ever registered and driven has been swapped to one.

 
Hello isaac300,

Lots of  good solid info so far. Like David very wisely stated, "Proceed with Caution". Nothing derails a project quicker than having a bunch of $$ tied up in a project and nothing fits or works!!

The part number for the bellhousing you need changed three different times. The original D1TZ-6392-A (ID# D1TA-AA) was replaced by D1TZ-6392-C (same ID# D1TA-AA) which was replaced a third and final time by D1TZ-6392-D (ID# D1TA-BA). These bell housings were actually sourced from the 240 and 300LD six cylinder engines found in the 66/ E and F series Ford trucks. The D1TZ bell housings were also used in the 69-79 F and E series with 302's.

There have been some Boss 351 owners with some very early built cars that have reported having a (C5TA-A) C5TZ-6392-A  bellhousing on their cars. The C5TZ was replaced by the D1TZ. The C5TZ housing is not listed in the Ford MPC for the Boss so was probably a temporary production line "Thing".  

If you can't find one listed for a Mustang, you could always try the truck angle since they are out there in greater numbers. (And maybe even cheaper)!

Using 72-73 applications since there are fewer choices than in 71, the most common tag numbers are RUG-BJ and RUG-BJ1for the transmissions.

I'm sure if you were to contact David Kee Top loaders via the link Hemikiller provided, he could provide you with way more useful trans fitment info that I ever could.

Good luck with either way you decide to go with your project.

 
Last edited by a moderator:
Back
Top