9 inch rear ID

Watching the threads on here, and reading and old article in the Mustng & Ford tech archives about 9 inch rear ID has me wondering.
I have a 9 inch with the bulge for the ring gear, which according to the article is 1967 to 80.

BUT, the axle tubes taper just before the springs, which according to the article is pre 67? So according to this article, I have a 67 or later housing that has pre 67 axle tubes? Any anomalies you all know of out there. Tried to find some casting numbers on the housing and hogshead (ya'll call it a pumpkin, but us folks in Carolina alway called it a hogshead), but have not located any numbers yet, where do they hide those?
Thanks

Originally Posted by Gydyup

Watching the threads on here, and reading and old article in the Mustng & Ford tech archives about 9 inch rear ID has me wondering.
I have a 9 inch with the bulge for the ring gear, which according to the article is 1967 to 80.

BUT, the axle tubes taper just before the springs, which according to the article is pre 67? So according to this article, I have a 67 or later housing that has pre 67 axle tubes? Any anomalies you all know of out there. Tried to find some casting numbers on the housing and hogshead (ya'll call it a pumpkin, but us folks in Carolina alway called it a hogshead), but have not located any numbers yet, where do they hide those?
Thanks

My 69 Mach one has the original 9" and my tubes taper also. So did the 67-70 big block cars including the CJs and SCJs. They all had the small diameter axle bearing. The auto cars, unless specifically ordered with the heavy duty option, had 28 spline axles. Same for the manual tranny apps. The heavy duty units had 31 spline axles but still the tubes tapered. Check out this link Kevinstang's Ford Nine Inch Differential Page +. By the way, in my part of VA we call it a "Third Member".

Thats good news on the rear, I was wondering if I had some frankenstien member, but it all looks factory.

Your not too far up the road, I am actually living in Southern VA now. You going to the Fast Fords at Dinwiddie? I was going to PM you to see if your taking your car.