Ford 9 inch, pro's and con's

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orangecrush

orangecrush

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Let me firt say that on this particular car (/6 Duster going V8) I am not at all concerned about originality, that being said. I came across a complete Ford 9" for a hundred bucks, not sure if posi or gear ratio. I know I am not going to find an 8 3/4 complete for less than 5-600.00 (or more) and I'm trying to build this car as inexpensively as possible. How are the 9" as far as adapting expense, and would this be the best route to take - why or why not - please don't respond if you can't give technical advise - I don't need to hear about hating Fords or staying all Mopar - this is a toy for me, been there and done the correct resto's if the 8 3/4 were reasonable, I'd be going that route, but .....
 
[quote=orangecrush;404467I don't need to hear about hating Fords



You may not need to...but your going to anyway. LOL J/K.

Good luck.
 
Ok,will the 9" fit without cutting??...if not, your going to have to pay to have it cut down thats 100.00,and the axles cut down too..if it does'nt have a sure grip thats another $400-500 you'll be putting in it,if it does'nt have the gears you want..theres another 230.00 plus the price of setting them up..an 8 3/4 with the dimensions for your car does'nt look to bad at 5-600 does it ??...
 
One advantage that I can think of - more deals on the 9" rears and parts thereof (look on Craigslist). I believe you could build a sure-grip 3.91 (3.73) equivalent for less.
 
First, will the car always be a /6 car? If so, Why not an 8 inch Ford rear? Those are a dime a dozen in Falcons and Comets, and way stronger than an 7.25 and SUPER CHEAP. My friend just gave one away.

Second, whats the width of the 9 inch you bought?

Falcon/Comet (and some other old little ford cars I think) 9 inches were pretty close to A-Body width (although very hard to get a hold of, much like an A-Body 8.75), some guys snag those and just get the correct Mopar spring perches in the right location.

To me the point to be made is this: are you going to have to narrow the housing at all? If so, you will be into it damn near as much as an 8.75 and then you have a heavy *** rear end. The weight difference is noticeable when you pick one up. If you aren't concerned about weight, then go for it if it will be a more affordable route.
 
If you are looking for bang for the buck check into a 94 up mustang GT rear they came standard with rear disk almost all of them were posi and you can pick one up for $250.00 - $300.00 complete. Also they will hold up well unless you are running super high HP. I'm not sure about width but it would be easy to find out check out forums.corral.net/forums for info and parts.
 
Is the pinion on an 8" and 9" Ford offset like a Mopar? I read somewhere that the Mopar rear ends have a 1.5 offset to the passenger side from the centerline of the axle.
 
I think the only bolt in 9'' would be from a 64-66 Mustang and those are hard to find and cost as much as an A body 8 3/4.You can use a B Body rear but you will loose tire room. Jim
 
The '57-'59 Ford Car rear end is supposed to be the same length as the 8 3/4 rear. I've got one spotted at a junk yard but don't know if the pinion has the same offset as the Mopar.
 
if the 9 inch you have is correct in width,,use it,,only other thing to mention is,, the BIG difference in a 9 inch compared to any rear end is ; it wil rob about 30 horse power over any other rear axel,,meaning it takes more horse power to turn the rear due to a heavy duty pinion bearing,,,you can read about it on a site call ed the H.A.M.B.
 
this may be a bit of an old thread, but i thought i would put a little bit of info in here, as i am considering doing the same thing- i already have a 31 spline ford 9" out of a truck, set up with 3.55s (not in the car). i want to say though, for a gearset you are looking at about $140+set up, and for a trac lok (ford equiv. to suregrip) you are looking at about 300 for a completely new unit. an alternative would be to FIND one with trac lok, and then cut it down and have the shafts resplined or buy a new set of shafts for... relatively cheap, at least compared to a mopar rear end. not bashing mopar rears, i would love to go with an 8.75, but MAN they're expensive!
 
The mopar rear is pretty cheap if you've got a duster/demon/barracuda and use a 65-70 model year 8 3/4. $150 for the housing and axles is about the going rate. Nice sure-grip centers are less than $500. slap all that together and move the spring pads in 1/2" and you're set.

In the duster/demon/barracuda you just need wheels with a bit more backspacing. Tires still fit fine in the wheelwells.
 
Id go 9 inch if i was you....I got a great deal on my 8-3/4, but if i didnt i think i would have gone 9 inch...if you can get it for 100 bucks i say take it....dont know how mechanically inclined you are, but you could always narrow it yourself? of course youd have to build a jig but its just an idea...also, 9 inch parts are much more common than 8-3/4 so you may be able to find a trac lok for sale used somewhere or if you scrounge junkyards you may find one as well...same goes for gears...the 9 inch does take more power than any other rear to actually turn, but it is strong (known fact) and has lots of parts available...i say go for it- who cares about staying mopar, if its strong and it works for cheap, then go for it!
 
hmmm.... goldduster, i've been looking around for one, and really haven't found a lot for the prices you're talking here. another thing is, the ford trucks (which you can get rears out of for dirt cheap) already come with 3.55s or 3.50s, depending on the year, which is a gear ratio that is popular in our applications. i guess the prices are comparable, considering what would need to be done to the 9". the other thing not so appealing is that they're like the 350 chevy of rear axles, and have no real special quality at all. this is a curse and a blessing, as it is hard to find 8.75s and easy to find 9"s.

a jig would consist of a couple pieces of angle iron and some nice big C clamps for your spots, and then one angle iron and a couple Cs to go around the whole thing.

i would also like to mention that i said trac lok is the equivalent, it is not the same thing. different type of clutch "disc." just in case anyone was going to go there...
 
if you want real strength out of a 9", you throw out everything but the stamped steel housing. The stock parts are inferior to the 8.75. IIRC, all stock 9" have 28 spline axles, and if you don't have a nodular iron center you'll bust that too.

Pinion diameter is also smaller on a 9" than even the 741 8.75.

I just contacted a guy who was parting a run of the mill 4-door satellite for mine. If you check the various mopar site classifieds you'd be able to find one if your patient.
 
car 9s have 28. truck 9s are 31. i promise :D
IMHO, the two are similar in strength.
problem with the classifieds here is that it's from all over the US (if not the world) and so usually the shipping would totally kill the deal.

BTW, i would really like to hear from someone who has put a 9 inch into their car, if there's anyone out there reading.... i would be interested in exactly what needed to be done.
 
ok, i've done a bit more research. i have to say, the 8.75 and the 9 are both good rear ends. i have no problem with mopar, in fact... i love mopar, and if i could find one that i could afford, i would buy a 8.75, as long as i didn't have to pay shipping. but even then, i will probably have to get a different set of gears, as well as the rest of a rebuild kit, and probably need a suregrip as well... adds up sorta fast...
 
There is a reason lots of people use the 9 inch. Strength, cost and avaliability. Most of these guys swear by the 8 3/4. Ive heard that some of the earlier ford cars like comets,falcons and mavricks there 9 inch are very close to a A body size.
 
the funny thing is that you could ship an 8 3/4 by UPS if you took it all apart. Housing in one box, axles in one box, center in an HD bucket, brakes in another box. The heavy part is the center! The housing itself is feathery light!
 
Back in the day, I pulled a Mustang 8" out of a 65 mustang and bolted it into a 66 dart I had, as a cheap way to use some wheels I wanted to use. I might have had to change the u-joint, but the unit was a complete bolt-in. No changes to the mounting pads, or driveshaft, plugged in the e-brake ends into the 8", added the wheels and "away I went". Mustang 9" housings aren't cheap anymore, but the 9" should be a pretty easy swap. Don't remember the difference between Mustang and 57-59 ford housings, but it isn't much.
 
Even though this thread is 8 months old, why not use a b-body 8 3/4? They are still cheap ($100-$150 in my area). Granted, it may not have a suregrip or the gears you want but neither did the 9" you mentioned as far as you knew).
 
dusterracer said:
Back in the day, I pulled a Mustang 8" out of a 65 mustang and bolted it into a 66 dart I had, as a cheap way to use some wheels I wanted to use. I might have had to change the u-joint, but the unit was a complete bolt-in. No changes to the mounting pads, or driveshaft, plugged in the e-brake ends into the 8", added the wheels and "away I went". Mustang 9" housings aren't cheap anymore, but the 9" should be a pretty easy swap. Don't remember the difference between Mustang and 57-59 ford housings, but it isn't much.
Click to expand...


I've used the 57-59 9" in several of my cars, you do have to cut the shaft though, otherwise it is a bolt in. The Mustang rear is about a 1/2"-1" wider than the stock rear while the 57-59 is a 1/2" narower than the stock rear. The perches are the same though.

There are aftermarket axles available now though for the A-Body 8 3/4 so that is the way to go unless you are running big horsepower and a 4spd then I would go with the 9" The 8 3/4 is more than enough for most street/strip cars though, I've switched the 9" out of my Dart for an 8 3/4 now.
 
aren't the bbody rears wider than the a bodies. The old fords were almost exactly the same width and spring perches were the same -- no alterations.
 
GTXperience said:
Even though this thread is 8 months old, why not use a b-body 8 3/4? They are still cheap ($100-$150 in my area). Granted, it may not have a suregrip or the gears you want but neither did the 9" you mentioned as far as you knew).
Click to expand...

The B-Body rear is 3" too wide for an A-Body they won't fit the early A-Body's at all without the tires rubbing the fender wells, and you have to move the perches to fit the spings.
 
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