3 sp standard to 4 sp standard????

You probably want a open ratio (2.78 1st as opposed to the closed ratio 2.32 1st) Toploader with the small input/output shaft. Some closed ratio trannys had small in/out behind 390's and they'll work, just the 1st gear is different.

A toploader is called that because there is a top plate that the gears go into, the case doesn't split open to service. Your 3 speed is a top loader. Some Mustangs also came with a T-10 4-speed which will also work, but by most, is less desirable. A toploader is stronger, the Jerico tranny is designed from the toploader.

The numbers or codes are only needed if your trying to "match" the tranny to the year of the car, but since your car came with a 3-speed, its probably not that big of a deal. The only thing your looking for is the right length tailshaft housing.

Your bellhousing will work, if memory serves, all you need is the tranny and a shifter with its linkage. If the 3-speed bellhousing won't work, Ebay has cast iron ones cheap, or you can get a Lakewood off ebay pretty cheap.

All 4-speeds are not toploaders, the T-10 isn't. Also, not all toploaders are 4-speeds. Your 3-speed is one, but a late model 3+1 looks like a 4-speed but is really a 3-speed with an overdrive. This is where understanding part numbers comes in. The tranny you want will probably start with a D3 or earlier ('73). These 3+1 are also recognixed by a bump on the front passenger side that helps to differentiate them.

If you get the right tranny, you shouldn't have to modify the drive shaft or anything. It just bolts in.

I took the 3-speed out of my '65 coupe and put in a 4-speed from a Boss 351. I had the shifter, linkage, tranny and bellhousing. I used my clutch, pressure plate, clutch fork and throw-out bearing, and the yoke that was on the front of the driveshaft that was in my car. The Boss cars came with a Hurst Shifter, so my 3-speed boot didn't work, but most parts stores have these on the shelf. Even the Speedo cable went into the tranny.

A good place to look is on Ebay, there you can find pictures of similar items. A '79 4-speed is not going to be a top loader, probably a T-10 or some sort of Borg Warner. Study before you just go off and buy something. That tranny will work in your car, but you may have to do some modifications. A t-5 is also an option, lots of guys change over to the cable style linkage from the old z-bar type.

A 390 specific Toploader will not work with the smallblock bellhousing, the input shaft is too short, leaving the input unsupported by the pilot bearing. He needs a small b-Mustang specific Toploader for a trouble free swap.

David, you've probably forgotten more than I know about Toploaders, but isn't there an extended bearing for that? I've seen people weld an extension onto those shorter that seemed to have held up in pretty much stock applications, not that I recommend it.

You need to make sure of a couple things:
1) You must get a short tailshaft tranny. The longer version was never available for the Stang and in short, would NOT be a direct swap for your 3 speed.
2) Make sure the tranny is out of a 289, 302,351c/w application. If you do use the FE version, it WILL need a special crank bushing, and therefore would not be a direct swap for your 3 speed.
If you get the right toploader, all you would have to do is unbolt the current tranny from your bell and insert the new. You will need a new shifter, but assuming your clutch and linkage are good, it's just a stab and go swap.
Once you try to adapt something or stray from the topload design, it is hit and miss how much fabbing and adapting you will need to do. Kinda equals more work and money if you stray from a bolt in.
Get the wide ratio tranny. It has a better gear spread for street driving and doesn't require as low a rear gear for performance useage.
You sound like you should just spend a few extra bux and get a 'new' tranny from a rebuilder.
There are several folks that rebuild the toploader... all you would have to do is pick up a shifter and stab the tranny they ship you.
Just tell them you want a Stang Toploader, wide ratio, for a small block.
They will hook you up for 'plug and play'.
Good luck
Dave

1320stang said:

David, you've probably forgotten more than I know about Toploaders, but isn't there an extended bearing for that? I've seen people weld an extension onto those shorter that seemed to have held up in pretty much stock applications, not that I recommend it.

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Yes, your correct Larry on the extended pilot bushing, but I've never seen them advertised anywhere, wouldn't know where to get one, other than to have one machined from scratch.

You mean I wasn't correct about you forgetting more than I know?

I was a little cryptic on the welding thing. What I meant was, I've seen people weld an extension on the shorter 390 input shaft to where it would engage the regular pilot bushing. Of course, this requires removing the input from the tranny and doing some lathe work to ensure it's true, not something everyone has access to.

1320stang said:

You mean I wasn't correct about you forgetting more than I know?

I was a little cryptic on the welding thing. What I meant was, I've seen people weld an extension on the shorter 390 input shaft to where it would engage the regular pilot bushing. Of course, this requires removing the input from the tranny and doing some lathe work to ensure it's true, not something everyone has access to.

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Instead of welding, you'd be better off just buying a new extended input from David Kee or another Toploader vendor. To do the welding and machining, will cost plenty ( for a quality job) and requires disassembling the whole transmission, as would replacing the input. So it would be faster and probably cost just as much to simply replace it.

Oh, I know, I saw these years ago, matter of fact, I think Dan Williams used to offer this service. I could be wrong on that though.