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Factory big bolt pattern demon

383 a4 runner

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In the early 90’s when my dad was building his duster drag car he was looking for 8 3/4 a body axles. On two separate occasions we found big bolt pattern 8 3/4 a body axles and both were in dodge demons. I’m not sure if they were 71 or 72 or 318 or 340. My guess is they were possibly late 72 production but that raises another question that I will address. Side note, neither set had been cut and resplined. My other question is was there any 8 3/4 a body cars built in 73-74? (I believe 73 was the first year for big bolt a bodies. Our 74 360 duster was big bolt but had the 8 1/4 rear. My dad actually still has one set of the axles. After the first set broke on launch he ordered moser axles.
 
There never was a big bolt standard A body 8 3/4" axle EXCEPT maybe the '68 Hemi Dart and Barracuda models.
It is easy to stumble across a modified part that is 50 years old that looks original....the years of grease, dirt and rust scale give you the impression that it is an original part. Stuff got modified when it was new or a few years old and 45-50 years later, it can appear to be a factory part.
Try this....Take a 2015 Challenger and swap in a Cummins diesel, then wait until 2071 and tell people that it was built that way!

1 laugh 5.gif
 
There never was a big bolt standard A body 8 3/4" axle EXCEPT maybe the '68 Hemi Dart and Barracuda models.
It is easy to stumble across a modified part that is 50 years old that looks original....the years of grease, dirt and rust scale give you the impression that it is an original part. Stuff got modified when it was new or a few years old and 45-50 years later, it can appear to be a factory part.
Try this....Take a 2015 Challenger and swap in a Cummins diesel, then wait until 2071 and tell people that it was built that way!

View attachment 1309941
That’s true but what are the odds of finding two sets? Both are completely identical in length, spline machining etc. what are the odds of two machine shops replicating factory taper identically? I’ve saw dozens of axles that have been cut down and resplined and every set did not match with any factory axle machine work.
 
Rockauto or any auto parts store should be able to give you that information, since hubs, rotors, drums, rims and more would be different parts than what is normally expected.
 
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That’s true but what are the odds of finding two sets? Both are completely identical in length, spline machining etc. what are the odds of two machine shops replicating factory taper identically? I’ve saw dozens of axles that have been cut down and resplined and every set did not match with any factory axle machine work.
It’s possible that the Demoms had B-body rear ends in them. 65-67 rear ends would easily fit with just moving the spring perches.
 
In the early 90’s when my dad was building his duster drag car he was looking for 8 3/4 a body axles. On two separate occasions we found big bolt pattern 8 3/4 a body axles and both were in dodge demons. I’m not sure if they were 71 or 72 or 318 or 340. My guess is they were possibly late 72 production but that raises another question that I will address. Side note, neither set had been cut and resplined. My other question is was there any 8 3/4 a body cars built in 73-74? (I believe 73 was the first year for big bolt a bodies. Our 74 360 duster was big bolt but had the 8 1/4 rear. My dad actually still has one set of the axles. After the first set broke on launch he ordered moser axles.
How can you tell that they were not resplined? Back in the day we had Moser do many and when we got them back they looked just like new factory axles.
 
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Another thing Moser did was weld up the small pattern holes and re-drill and stud for the large pattern. That was very common and when done right very hard to tell. We had lots of those done. Not all could be done as the flange area was a smaller diameter and Moser did not recommend doing those.
 
Another thing Moser did was weld up the small pattern holes and re-drill and stud for the large pattern. That was very common and when done right very hard to tell. We had lots of those done. Not all could be done as the flange area was a smaller diameter and Moser did not recommend doing those.
I’m not sure why they would have. They were bone stock mostly original cars. They were also on separate ends of the state. The cars were only 20 years old at the time. They were not b body rears either because we installed the axles in the rear we already had.
 
I’m not sure why they would have. They were bone stock mostly original cars. They were also on separate ends of the state. The cars were only 20 years old at the time. They were not b body rears either because we installed the axles in the rear we already had.
Ok you have your answers. What was the question.
 
Disk brakes got BBP.

Early ones didn't but 72/73 was the start IIRC.
 
Weren't A-bodies available in 72/73 with large bolt pattern. Not sure whether they were standard or an option. Was at a Dodge dealer in 1978 and saw a Dart on a lift no hub caps. Asked pats guy if that was a large pattern, yes it was. It was his daughters car with a 318.
 
I've had several '73 340 Dusters that had the BBP. BUT THOSE CAME WITH THE 8.25" REAR. Never, ever have I seen a factory A-Body 8.75" with BBP and I have had a ton of them.
 
72bluNblu might be the go-to on Abodies..
FWIW, my '69 8-3/4 axle flanges (with 10 X 1-3/4 brakes) were too small diameter for press in studs. The 5 on 4" 7/16" holes were filled, then drilled and tapped for screw in 1/2-20s on the 4-1/2" BC...
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