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What rearend with disk brake conversion is best for 850 horsepower?

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Old Nov 24, 2023 | 01:45 PM
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Break my Bank's Avatar
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What rearend with disk brake conversion is best for 850 horsepower?

Good day everyone, needing to ask you all a question. I'm currently restoring my first car I bought in 8th grade which is a 92 Rs 25th anniversary. I'm currently putting in a LT5 hot cam motor which is right at 850 horse, might put a small nitrous kit for show at car shows and some track use. I'm torn on the best rearend for this car to make a disk break conversion and also durability. What rear-end are you running or what do you suggest.
thank ythank advance
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Old Nov 24, 2023 | 03:00 PM
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Re: What rearend with disk brake conversion is best for 850 horsepower?

Don't waste time and money trying to improve a stock axle. Look at aftermarket 12 bolt, Ford 9", Strange S60.

Strange makes the 12 bolt and S60. Midwest Chassis probably makes the best fitting Ford 9". Hawks Motorsports can put together a Ford 8.8 as well. There are other companies like Moser, Mark Williams, Quick Performance.
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Old Nov 25, 2023 | 10:33 PM
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Re: What rearend with disk brake conversion is best for 850 horsepower?

What he said ^ ...
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Old Nov 29, 2023 | 02:56 PM
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Re: What rearend with disk brake conversion is best for 850 horsepower?

Midwest Chassis fab 9! Best bang for the buck. I absolutely love mine. Super smooth and bolts in the car just like the factory 10 bolt
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Old Nov 29, 2023 | 05:51 PM
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Car: '89 Firebird
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Re: What rearend with disk brake conversion is best for 850 horsepower?

No, a 12-bolt drops in like a 10-bolt. Same axle tube diameter, same torque arm mounts, same mounting brackets. All the aftermarket stuff for our cars fits it.

A Ford 9" bolts in like a Ford 9". Everything is specific to that axle.
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Old Nov 29, 2023 | 07:03 PM
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Re: What rearend with disk brake conversion is best for 850 horsepower?

It also depends on what transmission you are going to run. All of the afore mentioned rear ends are a massive upgrade over a 10bolt, but if you are running a manual transmission the ford 9" can't be beat. The double pinion design is practically immune to the drive line shock of a manual transmission. You can also run fixed brake calipers since it's a non floating axle (this is assuming you have fixed calipers up front given your power level). There can be more fitment headaches from a floor pan perspective, as Qwk points out, but having a swappable mid section to change gears is also a hidden benefit.

Edit: If you go 9" there are F-body specific options out there so they bolt in like stock.

Last edited by ShiftyCapone; Nov 29, 2023 at 07:09 PM.
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Old Nov 29, 2023 | 08:13 PM
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Re: What rearend with disk brake conversion is best for 850 horsepower?

I would recommend a 12-Bolt with Ford Style Axle Retention.

Most 9" Diff Housings are Terrible with Flex and Twisting unless you spend a lot of $$$ on Aftermarket Support that address those issues.

...And the Dana 60 is just over-kill and IMHO Consumes more than it's worth unless you are making 2,000 Ft/ Lbs of Torque!
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