10 Bolt to 14 Bolt Full Floater Swap

[stutaeng]

It didn't sound like OP is intended in racing his truck based on the initial post...

But good information on the 9" Ford. I always wondered why they are popular. My nephew has a souped up GMT 400 ECSB with a LQ4/nitrous/TH400 and some slicks. Last year he was thinking of upgrading his rear end. He was thinking about the Ford axle, but decided instead to beef up his 8.5" I haven't asked him how it's holding up, but I'm assuming he hasn't blown it up yet...

 

[Schurkey]

Ahem...

www.motortrend.com/how-to/9-inch-ford-rearend-strongest-rearend-due-hypoid-distance/

The greater "Hypoid distance" also means the axle takes more power to turn, by a percent or three.

The "competitive axles" they're talking about are passenger-car axles, not "truck" axles like the 9.5 semi-float. So GM 8.2, 8.5 and 8 7/8, Chrysler 8 3/4, Dana 44, etc. Even then, I don't think there's a huge strength advantage for the Nine Inch over the 12-bolt, or the Mopar 8 3/4. There is a huge difference in aftermarket support, for the reasons I mentioned earlier.

It's not surprising that a "fully built" Nine Inch is "stronger" than a (stock) Dana 60. The "Fully Built" nine-inch has thousands of dollars worth of Aftermarket Everything; they throw away anything with a Ford part number.

 

[MrPink]

The 9" is the same between the truck platforms and the car platforms so there is no difference in performance just overall width and how it gets mounted in the chassis. GM NEVER USED the 14B 9.5" SF in anything but a truck, because it is not a performance oriented axle. Ford when developing the 9" made it to out perform all axles that were avail in 1957 when it was released, and it was only behind a 300hp powertrain.

 

[stutaeng]

Wasn't there a 14 bolt 5 lug on one of them large Buicks with the LT1 engine? Not a performance, super fast car, but a car (or station wagon) nonetheless, LOL.

 

[MrPink]

Wasn't there a 14 bolt 5 lug on one of them large Buicks with the LT1 engine? Not a performance, super fast car, but a car (or station wagon) nonetheless, LOL.

not that i can remember no they all had variations of the 10 bolt.

 

[stutaeng]

not that i can remember no they all had variations of the 10 bolt.

I remember reading about it here. I think I even posted a photo of one I had found online...it was towing a good sized RV trailer, lol.

 

[Schurkey]

The 9" is the same between the truck platforms and the car platforms so there is no difference in performance

There's MANY differences in the various versions of the Ford Nine Inch, over the years and depending on the application.

Grey iron case vs. nodular iron case, axle bearing sizes, pinion bearing sizes, axle shaft diameter and spline count...have you ever known Ford to not make five variations of everything they've ever built?

 

[Frank Enstein]

I have 3 pens worth of notes in my Ratech catalog on the 9 inch Ford page!

 

[Erik the Awful]

It boils down to intent. If Brad intends to build a 9000 rpm motor, a 14 bolt is not the way to go. The weight is just not worth it. Neither is a 9". If it's "not intended to be a race truck", the motor itself is not the way to go. Either get that truck down under 3500 lbs, or build a torque motor.

Schurkey, if you don't like Fords, just say it. The 8.8" is a perfectly good option, and is comparable in weight to a 10 bolt while being about as strong as a 12 bolt.

Here's the rankings as I see them. Dana 60 (500 lbs) > 14 bolt FF (400 lbs) > 9" (400 lbs) > 14 bolt SF (400 lbs) > 12 bolt (230 lbs) = 8.8" (200 lbs) > 10 bolt (200 lbs)

the WMS measurement will be way off on the exploder 8.8 they measure 59.5" WMS to WMS, our trucks are 65" WMS to WMS for the 10 bolt.

If you buy an Explorer 8.8 and an extra passenger side axle you can widen it to 62.5" fairly easily, which isn't way off. The difficulty is finding an extra section of tube. Buy two 8.8s, narrow one and extend the other and sell the narrowed one for the cost of both! Winning!

Otherwise I see your options as:
1) Try to get down to a weight where the 10 bolt will survive with $1000 worth of upgrades
2) Find a 12 bolt and pay $1000 before you even start upgrading

 

[MrPink]

yeah there is always the 80-96 F150 8.8 too if he doesn't want to re-tube the axle. They measure 65.25" in WMS-WMS, but he would have to do a disk conversion and rarely did they come with a LSD but they(the axle asm) can be had for $50-150, and should be 31 spline too.

Personally I am going with a 9" only because I can get one cheap, and build it cheapish. I need a axle that will handle ~800hp at most, and the 9" can manage that pretty easy.