84 F-150 axle code H6

Now I know from researching (correct me if wrong) that H6 means a 9" 3:50 gear ratio, limited slip. What I don't know is if it is a 28 or 31 spline unit, I looked all over but this detail is never included. The VIN: 1FTEF15G8EPA31768. Trans code K on the door tag (C6 Auto), Engine code G on the vin (5.2L 351c.i. v-8 2bbl 150hp). I have to know this before I have the yard pull the part. THANKS!

Hay Ken
Check this page, at the bottom is a list of Differntal codes click on yours and it should give its perticulars.
FORDification.com - Decoding Your Ford Rearend's Axle Tag - Page 1 of 17
Tim

Yeah, sorry forgot to mention that the damn diff tag is GONE, which is what is making it even more difficult. I will look at that link and see what I can gather though............................................ ...Fast forward an hour later............................................. .........OK. I have printed and searched that whole line up of diff codes. Can you believe that the 3:50 ratio is the ONLY one not on there? This is supposed to be my hobby but I feel like Im gonna lose my mind! The 80-86 F-150 in 3:00,3:25, and 4:11 in 9" are all said to be 31 spline, but NL (non-locking). Yet the damn door tag code says H6 which is 3:50 and limited slip. Is NL and limited slip the same thing? Why the HELL is the 3:50 the only one not listed for the 84 F-150??? OMG Im gonna go out and get a smoke. Wait, I dont smoke. No matter.

Can you vairafi the Ratio by counting the revalution of the Driveline to tire.. Maybe its not a 350 gear?
Tim

Well its in a yard, so I suppose if I were to ask it would be possible. I just really needed to know the spline because I would have to either get axles, or new side gears. Now, I can see getting new side gears to upgrade to 31 spline, but to downgrade to 28?? No, I dont think so. I hate to do this, but I think Im going to have them pull the part and if it isnt what I want, I simply wont take it is all. I am going to do what I can to be there when the part is pulled so I can get a look at the axles myself. The 28s are tapered and the 31s are not, that simple right?? Shoot, I'll even count the splines! It is most likely a 31 since the other ratios were as well. What I won't do is pay for the part UNTIL I see it and it is what I want. This find is the result of alot of reading and self teaching. Alot of crawling under junk trucks while I was on patrol in the street. It cracks me up that the first junkyard I look through and I find one! For $125 no less! I think I got lucky with it, but I swear, if this hobby is always this frustrating, Im gonna take up bird watching instead! LOL

yea the only real way is to pull em and count... any kind of modifacation takes a lot of looking & waiting .
Watch out for that bird watching.. you might get called a peeping Tom (Ken) if your watching in the city.. LOL...
Tim

I ran in to this problem when trying to get a wrecking yard Dif for my 79 ford , I was told if it is a 100 they have 28 spline . A F 150 has 31 spline in all ratios posi. or open .