Need some 9inch advice. Vehicle related

[abrahamfh]

Good morning to all,
   Last night I found a lead on a local with what seems to be a few 65-66 mustang 9inch rear ends.
   What are the pro's and con's to the 9 inch?
   What would warrant swapping your 8 inch for a 9 inch?
   What would be a reasonable price?
   Even if I am not ready for it, would it be wise to move on a offer like this one?

Here is the email he sent me last night.
 
"Hello Abraham - I am flexible on pricing but generally I would like to get:
 
1) ~$500-$550ish for a standard 9 inch complete
2) ~$700-$750ish for a complete 9 inch with spool
3) ~$1000 ish for a complete 9 inch posi
 
Call me if you are interested in talking more on pricing. I have tons of Mustang parts and can make you a great package deal or if you don't want a complete rear end, I have parts galore."

Thanks in advance everyone for your input.

[AzPete]

9" is pretty much bullet proof, weighs more, costs a bit more to repair if you ever need to.

Not needed for strength unless you are floating around 400HP or more.

The "chunk", rebuilt/new with posi runs $1000+ based on where you shop.

I have been looking for a good 8" posi with 3:25 gears and they are hard to find as everyone has 9" and "can get" me an 8" for close to the same price. I just thought it would be cheaper to keep my housing and axles....

[camachinist]

At those price levels, unless you know how to evaluate the condition of a rear end assembly, I'd pass. That's expensive or, at best, definitely no bargain.

My rule of thumb has traditionally been, over 2700lbs and/or 400hp and/or manual transmission and/or slicks and/or racing, go with the 9" .

You can break an 8" with a standard hi-po, manual transmission and slicks in a relatively stock weight Mustang. That's around 280 hp but applied harshly and at high rpm. On normal street tires it would be totally different, but still a maintenance item due to stress. Pinion spitting is the most common issue I saw during my racing career.

Pat

[sigtauenus]

1) ~$500-$550ish for a standard 9 inch complete
2) ~$700-$750ish for a complete 9 inch with spool
3) ~$1000 ish for a complete 9 inch traction-lok

First off, don't buy anything with Chevy parts.

As for prices, are those rebuilt?  If so, those are fair prices, but nothing eye watering or warranting a change to your timeline.

[66gt350]

I recently bought a new pumpkin for my 9", with brand new gears and a new Eaton True-trac for just a hair over $1000.

[sigtauenus]

I'm basing this on mine...

Housing robbed from parts car - free for me, but generally $250-300 for a Mustang housing (correct widths).

Axles are 28 spline, I had recently changed bearings on my 8" so I used the axles from my 8".  They are the same.

Center section was open, I had it rebuilt with new Strange 3.50 gears, Ford traction-lock unit, obviously with new bearings, for $850.  BUT, if I had shopped around, I probably could have picked something up similar with no core on ebay for the same price.

[Jonk67]

I got what I thought was a fair deal but had the time to wait. Bought a '69 Cougar 9" off CL, picked it up for ~$200 complete to the drums. Tried to win a 9" 3.50:1 tracloc on fleabay and the seller contacted saying he would build me one, close enough to drive. I traded him my old 8" peg leg and the conv. 3rd member from my CL 9" and got the new built unit for $350. So for ~$500-$600 I have a fresh 9" 3.50:1 tracloc which I shouldn't be able to break with an AOD and 400hp. I think the shorter '65-'66 units are getting harder to find. I wouldn't spend $1K+ unless it was newly rebuilt by a reputable shop with warranty IMO.
Jon

[abrahamfh]

So I replied to the email trying to verify if what he has is truly for a 65 66 and he stated that he does have 9inch but quoted me 2.5k for it. Yikes?

He is recommending leaving what I have but replacing the third member with a 9 inch?
Is this even possible/safe?

His response,

"1) Take the non mustang 9 inch for the quoted price.
2) If your mustang is a V8 car, replace the 8 inch with a 9 inch 3rd member
3) Buy the Shelby 9 inch for $2.5 k"

[sigtauenus]

It is physically impossible to put a 9" center section into a 8" housing.  If you have a 8" rear right now, I have no idea what that guy is talking about. 

Personally I'm still wondering why a guy who deals with Ford rear ends like this is referring it to a "Posi."  The tech who comes to service your Canon copier doesn't ask if he can "xerox" the invoice does he?  Maybe I'm paranoid, but I read into attention to detail items like that regarding how seriously somebody takes their business. 

[garner67]

If you're gonna have somewhere close to 400hp, I'd go with a 9in.

Unless you can confirm the rear end has been properly rebuilt, those prices seem a bit high.  If you're patient you probably could find a complete 9in that needs a rebuild for less.  Keep in mind, if you want to install high end parts (axles, center section, gears, yokes, etc), it's easy to spend well over 2k on a rear end... add brakes and you're at 3k.

Why don't you check out the Currie site and build a complete 9in rear to see what it costs to build a brand new complete rear, including disc brakes.  If you go that route, you definitely won't be spending money twice.

Currie Enterprises (click the "build your crate rear end" button)

[abrahamfh]

It is physically impossible to put a 9" center section into a 8" housing.  If you have a 8" rear right now, I have no idea what that guy is talking about. 

Thats what I thought, due to the 8inch not having the added vertical hump on the back.

[buening]

Why don't you check out the Currie site and build a complete 9in rear to see what it costs to build a brand new complete rear, including disc brakes.  If you go that route, you definitely won't be spending money twice.

Currie Enterprises (click the "build your crate rear end" button)

Out of curiosity I just tried that.  The base price for housing and axles was a little over $1k.  Just adding the open differential and 3.00 gears bumped the price to $2300.   $1300 just for an open diff with gears?   :scar  The True Trac locker added another $300 to the price to a bit under $1600 for the differential.   I guess we are talking about a new differential housing, but dayum!

[daveSanborn]

but dayum!

The Currie rearend in my son's car was just under $3500.  Personally, I'd have not spent that kind of money, but that's what he wanted.

[sigtauenus]

The Currie rearend in my son's car was just under $3500.  Personally, I'd have not spent that kind of money, but that's what he wanted.

Well, it is easier to spend that kind of cash doing what your son does.  He can't really spend much on anything else where he's at.  My company is looking for volunteers for in-country support and when I saw the pay structure my eyes glazed over with thoughts of a EFI conversion and other goodies for the car.  Hell, new siding for the house, maybe a hot tub...  ;)

[daveSanborn]

Well, it is easier to spend that kind of cash doing what your son does.

My son works at Walmart.

[abrahamfh]

The Currie rearend in my son's car was just under $3500.  Personally, I'd have not spent that kind of money, but that's what he wanted.

Just to pick your brain a little Dave, what would Dave Sanborn do?

[garner67]

Just to pick your brain a little Dave, what would Dave Sanborn do?

Here's my guess for what Sanborn would do...

He'd find a great deal on an old housing and axles (center section may or may not be included).  Then, if necessary, he'd go out an find a locking center section.  To finish things off, he' rebuild the center section and possibly change the gears himself; then clean and repaint the whole thing.  Total $$$ spent between... $700 & $1200.

[66gt350]

Just to pick your brain a little Dave, what would Dave Sanborn do?

He'd make his own out of duct tape, baling wire and old beer cans.  :craz :craz

[Jonk67]

The main thing that pushed me to locate a 9" local and get a 3rd member from fleabay was the fact that I couldn't find a tracloc 8" 3rd member for less than $600-$800 so it ended up $100-$300 cheaper for me to switch to a 9", many more of them out there and I ended up with a stronger rear end.

I cleaned up my 9" and painted it, got the built 3rd member and bolted it into the housing, good to go, no worry about setting up the gears either.
Jon

[tarafied1]

My son works at Walmart.

In Iraq...

and I'm with Sig, if this guy thinks a 9" "posi" will fit in an 8" housing he clearly doesn't know what he is talking about!

[Midlife]

Just to pick your brain a little Dave, what would Dave Sanborn do?

He'd steal the system from his son's car, and swap it with an 8" open rear end.  The son wouldn't know what had happened, and except for Dave's time spent swapping things out, it would cost him nothing.

[gotstang]

I'd look for a 9" out of ANYTHING, the cheaper the better. Get it shortened and fork out the ~$500 for that and custom axles, add in a 3rd member of your choice and whichever brakes you'd like. It's the cheapest route to a 65-66 width 9" I've seen.

That said, you could do without a 9". 8" will live just fine on the street.

[AzPete]

Wish I could locate some of these low priced 8" posi chunks. Best I have found so far is about $700.

[johnpro]

I have a 9" in both my '66 and my '69 because I got killer deals on both.  In both rear ends, I'm into each about $500 for the '66 and $600 in the '69.  The '69 was more expensive because it's a 4 pinion 31 spline unit.

The 9" in the '66 is definitely overkill but it's fun to have the braggin' rights.

Both are traction-lok rears ... 3.50:1 in the '66 with an AOD, and 3.89:1 in the '69 with a Tremec TKO 600.

Oh, and not all 9" rears have the hump on the back.  '66 Mustang 9" rears don't.

[daveSanborn]

Just to pick your brain a little Dave, what would Dave Sanborn do?

The first thing I'd do is tell the seller you've mentioned to pack sand.  His prices are WAY TOO HIGH.


I assume that your existing 8" open is operating fine and the 9" upgrade is just one of those "things I'd like to do"?  This is usually the case.  If you're operating within a budget.... have patience and keep looking.  Like JohPro stated, the right deal will come along.  After you find, buy and make the swap you'll see complete units selling for less than you paid and you'll be kicking yourself.

I've made a few 9" swaps and have always scored deals due to patience.  If you "have to have it and it has to be NOW" you're going to pay.  I got a 9" 3.50 Trac-lok complete drum to drum out of a 67 S code car for nothing other than my labor to remove the 9" and install my old 8" open rearend.  I wasn't looking for a 9" for this car, the 8" was working just fine, but free is.... free.

My existing '66 came with a narrowed 9" housing/axles and a fully spooled 4.11.  I told the seller to keep the spool as I wasn't interested in it (I should have taken it and sold it though).  While I was building the car I searched eBay/Craigslist for 9" 3.50 geared Trac-lok units.  It took a few months... and I lost a few auctions, but I finally scored a used one from eBay seller "Jeff's Bronco Graveyard" (or something like that).  I won the auction at $202.50 and shipping killed me at almost $90, but under $300 for a 9" 3.50 geared Trac-lok isn't a bad deal.

Open up your search to other vehicles.  If you're searching for a "Mustang 9" rearend", you're going to pay through the nose.  As long as the 9" you find is wider than what you need, it can be easily and cheaply cut down/modified to fit your car.

Good luck!