K sounds like the trans code for C6.
Axle code is typically a 2 digit number, or number-letter combo.

 

thanks Rogue. That's what I figured too but 'K' is the only thing on the sticker anywhere close to the axle indicator, and there are no tags that I can see yet on the axle itself. All the axle code charts I've found so far have no reference to a 'K'. The trans code = CA4, which I thought meant it had a C4 tranny. Pretty sure that's what it had before I put the C6 in it.

Does anyone know what the factory axle would've been for this truck? Came with a 351W and C4 tranny originally.

 

There are any number of axles you could have had.

Someplace in this forum is a post by me with "axle codes" in the Title, I think it's a post in somebody else's thread but it's got the axle codes from the parts catalog in it.

Transmission codes are generally one digit, I think that information is up here someplace, too.

 

Regarding the differential ratio: If you can safely raise the truck, put the transmission in neutral and using chaulk or a piece of tape, mark each rear tire [we don't know if you have open or limited slip]. Slowly rotate your drive shaft and count how many turns the drive shaft makes before one or both tires makes one revolution. If it takes approximately 3 1/2 turns, then your rear ratio is either 3.50 or 3.55. If it takes slightly more than 4 turns, you have a 4.10. This will get you in the ball park.

 

If it was a 4wd, it came with a c6 originally. C4 is a little too light duty for the larger trucks, especially behind a 351w.

You do not have very many options with that old engine you have. The E4OD is the only option for a automatic, and as was said before, requires a computer and a bunch of wires to run it. It will work if you have the money.

The aftermarket overdrive unit will work, but everyone thinks they are made of gold, including the people who manufacture it.

I would say stick a zf 5 speed manual behind it, but there is a very very long thread on here somewhere discussing problems with getting it to fit up to the 351m/400 engine. Too bad you made that choice and put that engine in your truck. Those old engines are ok for the older trucks they came in, but not very practical as a swap engine into a newer truck.

 

If the Axle Code is missing on the lable, (weird), you might have a chance with the axle itself. Look for a tag on the axle. It should have the axle ratio in numbers like: 3.55 or 3L55 for limited slip, as example. Your ratio will vary... IE: 2.55 2L55 / 3.00 3L00 etc...

 

Thanks Franklin. At the time I went with the motor I had available. I didn't realize that a 400M was that much of an older motor than the 351W that came in the '84 truck.

 

Perfect, thanks !

 

Hey, post a picture of your door tag on here, if it's the sticker type door tag it should be in the bottom right area of the sticker. That's where mine is located anyways.

 

Somewhere around 83, the 351m/400's were done, no longer made. So it's downhill from there. Just like the FE family of engines (352/360/427/390)has been gone for years. But at least you put a motor in there that was actually offered in these style trucks. Some people insist on putting a 390 in these trucks. Go for it is what I say, but it doesn't make much sense, and the FE series of engines was never offered in this frame/body style.

 

One thinoling the E4OD, that aftermarket unit I linked to is about $450 and the harness is $150, so it is far cheaper then the gear vendor unit I listed. Also far better then Ford's stock ecu just because it allows full controll over shift point tuning etc.

 

thanks! I'll post my mftr tag shortly.

 

Thanks Franklin. Amazing what I'm learning on this forum. I'm a Ford fanatic all the way thru and thought I knew a little about them but pretty obvious how little my knowledge really is! Cheers.

 

Hmm... for some reason I can't post attachments. Until then I can't post my mftr label.

 

I have to upload pictures to my profile then click on "insert image" then put the picture URL in there and it should pop up.