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Hey guys I recently picked up a nine inch and did not think to much about the width of the axle. From my understanding it was pulled from a 79 f150. Now I noticed they are defiantly not the same width.


What years if any are the correct width?

That is from an earlier truck. Most likely 67-72.

FYI, you need a 80-85 axle to fit correctly. 78/79 may fit, with some minor differences.

That looks like an early Bronco 9.

I'm pretty sure the early bronco 9" are even narrower than what is shown Brian. In his pics the 9" only looks a few inches narrower overall - about 4" maybe, and I think the EB stuff is more than that. My EB 9" is in storage in long beach or I'd measure. I know they are perfect width for Model A type stuff which is what I'm using mine on. Keep in mind if that is a EB 9" somehow - that they are only 28 spline axles!

When measured this one is 4 inches shorter then my 8.8. If I were to find a 79 what changes would need to be made to bolt in.

If I remember right:

73-86 F100/F150/Bronco 9" rear ends are all the same width. 73-77 has 28 spline axles, 80-85 F100 had 5x4.5 pattern. 73-77 usually had different leaf spring perch spacing (narrower frames)
80-86 Bolts in.
78-79 had some small differences with shock mounts, yoke, or brakes (I can't remember what the difference was), housings may have early style big bearing ends.
Earlier stuff is more likely to have 3.00:1 ratio. Most had 3.50:1, 4.11:1 is rare.

From what I'm seeing the WMS to WMS of the early bronco (74-77's) are about 58.5 or so. That would be narrower than what you are showing.

1 other question - are you sure that is a 5.5" lug pattern. There were some cars that had the 9" rear with the 5x5 lug pattern.

Must be an early truck I think. Early bronco has leaf perches closer together and shock mounts on outside of perches. Car housing would probably have perches underneath not on top.

Just resell it and get an 80-85 F150/Bronco -- forget the 78/79 trucks as they are much harder to find and much less availability -- the 80-85 are fairly easily to find.

Agreed, but make that 80-87. Well, I have heard they were seen in trucks up to '87. I have personally seen them up to '86. Makes sense that they may run later though as I'm sure Ford used up what they had left of the 9" axles over time instead of just a dead stop with the 9" & making everything after a certain date an 8.8

My 86 Bronco Had the 8.8 stock where my 81 F100 had a 9" with 5 on 5.5 lug pattern.

My 86 bronco had a 9" stock. From what I have been told 8.8's found their way into broncos as early as '84 and 9"ers were in some stragglers til '87

The F-100's did have 5x4.5 lug pattern for a bit (ranger guys used to go after these axles), but I thought it was from 80-82. Maybe not all F-100's got the small lug pattern. I know the ones with the "swiss cheese" frames did, which means maybe it was just the lightest duty trucks that had the oddball lug pattern.

Uh oh here comes Cs_drums with his .02$!

I feel inclined anytime someone is building a 9" to preach a little.
I strongly believe this is one area where it seems more expensive but ends up not being to buy new, right the first time. There are so many variable with all the 9" out there that it is a real head ache. Many companies have fab housing for reasonable prices. Currie sells a HD stock style for cheap.

To really benifit the 8.8 to 9" swap you want to go 35 spline. So you already will be into it for axles regaurdless of housing.

Again like I said just my opinion after building one and buying one.

cs_drums wrote:Uh oh here comes Cs_drums with his .02$!

I feel inclined anytime someone is building a 9" to preach a little.
I strongly believe this is one area where it seems more expensive but ends up not being to buy new, right the first time. There are so many variable with all the 9" out there that it is a real head ache. Many companies have fab housing for reasonable prices. Currie sells a HD stock style for cheap.

To really benifit the 8.8 to 9" swap you want to go 35 spline. So you already will be into it for axles regaurdless of housing.

Again like I said just my opinion after building one and buying one.

X2.. Agree across the board on your comments for sure.