Thanks for the question.
There is no tag on the axle itself?
On the door sticker, are you sure it says c9? I'm not finding c9 under axle code for 1997 f250.
Yes if you could send me a picture, that would be great. Because in the Ford manual here, there is no c9 code for axle ratio for 1997 f250 diesel.
Did you attach the pictures to your last reply? I don't have them. I cannot see them in your last comment. In the top title bar where you type your message you should see a picture of a little tree. This is where you attach your pictures at.
Go to your profile page and go to tools and then edit your profile and then go to settings and then Advanced post tool and check yes.
Just for giggles, on the door sticker where it says AXLE under it it says "C9" ?
How about just sending me an email with the picture.
Thanks for the help Chris.
I got your picture Bill. I had to go all the way back to a 1995 F250 and found C9 and it said 3.55 ls (limited slip). These are Ford manuals I'm looking in. Even in 1996 f250 it wasn't there. Sorry for all of this. I'm not sure why for 2 years the Ford manual has been wrong on this. To be sure, another possible way to check is to look on the outside of the ring gear. And or on the pinion face. Look for the number 3.55 or 355 etc.
Sorry for the confusion.