Author Topic: Ford 9" to replace weak 10 bolt need fitment help  (Read 6173 times)

Offline Bigrig

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Ford 9" to replace weak 10 bolt need fitment help
« on: July 18, 2017, 08:51:43 AM »
New to the site !  Building a 86 Chevy 1/2 ton long bed 2wd.  Engine- 455 Olds fully built roller rockers aluminum ported heads , aluminum manifold, T400, Holly Demon 750 cm , long tube headers etc...  Way to much power for the little 10 bolt rear end.  I would like to swap a Ford 9" but do not want to have to cut one to fit the width.  Who has put a 9" in their 2wd ?  I need to know what stock 9" would work.  I am concerned with the width and understand I will have to cut off tabs and do some external modifications but DO NOT want to chop one down to fit the width.  Any advice , suggestions,  OEM vehicles with the correct widths would help ! 
Long Bed low and fast

Offline jetman

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #1 on: July 18, 2017, 10:59:22 AM »
Your 10 bolt rear end should have a WMS to WMS of about 63 1/2". Depending on wheel size and offset to be used, you may be able to source something ready to go from an old beater.  I believe the 1967-1973 model year Mustang, Torino, Ranchero, Fairlane had a WMS-WMS of 59.25 inches to 61.25 inches, which may be in the ballpark assuming you are going with some grippy tires.

Offline Stewart G Griffin

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #2 on: July 18, 2017, 08:40:02 PM »
i disagree and think the 8.5 10-bolt is strong enough.   Even then, it would be easier/cheaper to find a 12 bolt from from a pre-81 truck which would bolt in.   But the 10 bolt and 12 bolts are very close in strength, so that would be unnecessary too.

Also, if you are going to drive on the street w/street tires, then the tires would spin first before putting stress on the rear if the engine is really making that much power which would require something stronger than the 10-bolt.

The bottom line is i would leave it.

Offline Rattler12

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #3 on: July 18, 2017, 09:11:59 PM »
Agree with SGG.....I've got a 10 bolt in my 83 behind a pretty healthy 454 and have had no problems.......having said that if your 10 bolt is a gov lock, get rid of it or pull the carrier and replace it with a tru trac or similar......10 bolt are pretty strong if done right
83 C-10 shorty 454, 5spd, 3:73 posi

Offline jetman

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #4 on: July 19, 2017, 07:42:30 AM »
Yes, the 10 bolt is surprisingly strong for its size and typically will take a LOT of abuse before throwing in the towel.  But there are practical reasons the 9-inch enjoys a strong hot rod following. The removable third member makes gear changes MUCH easier than Salisbury-style (Dana) axles. Use of a removable pinion support and spanners instead of carrier shims makes gear setup EASY. And there are a nearly infinite number of gear ratios available for the 9-inch, from as high as 3.00 and as low as 6.50. The removable third member also means that the sheetmetal housing is not only lighter than a comparable Dana axle but can be easier to weld custom brackets for your suspension since you do not have to contend with GM’s cast center section.

The Ford gear design itself is responsible for the 9-inch’s reputation for holding up to High Horsepower. While the ring gear diameter is smaller than a Dana 60, pinion offset from the centerline is 2 1/4 inches for a 9-inch and 1 1/8 inches for a Dana 60. This is a tradeoff, because the Dana 60 will provide a better driveline angle and more ground clearance beneath the yoke, but the Ford 9-inch will have Better Tooth Engagement between the ring gear and pinion due to the angle of the teeth on the 9-inch design. And like a heavy GM Corporate 14-bolt FF axle, the Ford 9-inch has a third pinion bearing beyond the pinion teeth that minimizes gear deflection.

Lots of reasons beyond just “being strong”..

Offline Bigrig

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #5 on: July 20, 2017, 10:33:50 PM »
Ok good insight , So add a posi unit in the current 10 bolt and then let it ride.  That is a cheaper option for sure I just want to build it right the first time and not have to get stranded on the street or track.  great forum
Long Bed low and fast

Offline Captkaos

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #6 on: July 25, 2017, 11:28:35 PM »
I am running a factory 10 bolt on street tires with a Eaton LSD making 505lb/ft to the tires.  My brother is running 730lb/ft same setup and he has run them with drag slicks.

Offline Rattler12

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Re: Ford 9" to replace weak 10 bolt need fitment help
« Reply #7 on: July 26, 2017, 07:52:41 AM »
Sides itud be an abomination putting anything ford in a Chevy......... >:(   :D
83 C-10 shorty 454, 5spd, 3:73 posi