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You've got the early 9". They had the smooth, dimpled housing back similar to the 8", but the center is more round where the 8" is semi-oval shaped. You can verify by checking the nuts on the center section. On an 8" you can put a socket on all of them. A 9" requires a wrench to get at the ones directly underneath the pinion snout.
That's a peach of a truck, congratulations on your find!
If you have the original 9-inch center it will not have a fill plug in it since the fill plug was in the housing, in 68 when they went to bigger brakes on the rear, they eliminated the fill plug in the housing and started using a fill plug in the center. If you have both then the center has been changed for a newer model. The weak point of the original 28 spline 9-inch rears is the axles they are good for around 400 HP.
There's plenty of examples of early round back 9"ers having a fill plug in back. They may have come both ways depending on year and application. Another thing to check is the wheel lug bolt pattern. If it's the 5 on 5 1/2 there's no doubt it's an original truck axle. 8"s only came with the 5 on 4 1/2 car pattern.
One of the ways many people spot a 9″ rear end in the car is by looking for the hump in the center of housing, this is not always the best way, as 9″ housings made prior to sometime in 1966 do not have the this large center protrusion. The one shown above is out of a 63 Galaxie, note its roundish appearance, two dimples and fill plug in housing back. https://maliburacing.com/ford-nine-inch-g-body/
Congrats on a cool truck. I’m actually the opposite of you… I’ve been a ford guy my entire life, but sold my 64 galaxie and a classic turbo import a couple years ago to fund a 69 charger General Lee build.
Not a traitor, just found most later Fords (trucks) ugly lacking curb appeal. I do Love the styling of my 65 and 66 F250's. 50yrs of mostly 60-early 70s cars I have settled on Toyotas due to reliability. 2020 Tundra, 2008 Tacoma, 2007 FJ Cruiser and 2005 Celica.
I feel ya, when I bought a 1970 C10 I felt the same being a Ford guy, Ford family etc... never had anything against the others, and as my dad and granpa always said, "I'd rather drive anything then have to push the sob" so for me, there's no such thing as brand specific when it comes to old iron, I like the old stuff, it's built better, lasts longer and has more class and appeal than anything past the early 80's (with the exception of the OBS )
Great looking truck! Welcome to the Slickness! Def open up that 460 and make a beast!
One of the ways many people spot a 9″ rear end in the car is by looking for the hump in the center of housing, this is not always the best way, as 9″ housings made prior to sometime in 1966 do not have the this large center protrusion. The one shown above is out of a 63 Galaxie, note its roundish appearance, two dimples and fill plug in housing back. https://maliburacing.com/ford-nine-inch-g-body/
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from his granpa's dealership in NE so Ford's were in the blood so to say...
