Help decoding non-standard rear diff tag?

[bootstrapper]

I've already checked the tech library, and the tag on my rear diff doesn't seem to conform to those codes. The door tag is scuffed up and unreadable.

Here's what the diff tag says:

S302B
4575 8L21

It looks like the diff cover was replaced before I got the truck, so it might not be the original Ford tag. Any help would be appreciated before I go out and start swapping out a perfectly good axle!

Thanks in advance...

--
1992 2.3L 5spd

 

[Surrey]

You can always pull the cover off and look for the stamp on the ring gear - it will tell you what ratio it is.

 

[Snoranger]

S302B = 7.5 with 3.45 gears


http://www.fordification.com/tech/rearends_ford11.htm

 

[scotts90ranger]

On the bottom row, you have 4575, there's a 3 under the bolt head (or it's been flattened... they leave a space between there as that's where put the L or SL for limited slip) that's 3.45 and 7.5" axle as stated above, the bottom row is easier to decode without any special searches

 

[bootstrapper]

Awesome thanks. Looks like we're swappin

 

[bootstrapper]

So I found a salvage 7.5/4.10 from a 2000 ranger ($125). Is there any reason to think that wouldn't fit my 1992? A couple people have told me that certain years aren't interchangeable, but can't tell me why.

Thanks again!

 

[Snoranger]

So I found a salvage 7.5/4.10 from a 2000 ranger ($125). Is there any reason to think that wouldn't fit my 1992? A couple people have told me that certain years aren't interchangeable, but can't tell me why.

Thanks again!

'93+ will bolt up fine, but its a little wider.