Has anyone on here done this? I want to do this and there appears to be two different options out there available. How difficult is it to do.

Thanks
Pat

 

Are you talking about the kit that Fabcraft sells? I'm ready to do this to a 9.3 in a couple months, and was wondering myself. Everything else I bought from them in years past was top notch stuff

 

Yes, any information is appreciated. I'm not looking to make racecar but I need a little more gear and definitely a lsd.

 

I would be interested to hear what FabCraft has. I am not ready to put LSD in my '57, but I am researching now.
What I have learned from this site is '57-58 uses 29 spline axles and '59-64 uses 31 spline axles.
Also from this site, there seems to be no one producing ring and pinion sets in the 3.00 to 4.00 range.

 

Its not bad putting one together at least has thread adjusters for the ring gear like a 9" Ford so you wont have to buy a shim kit. Fabcraft on Ebay has the new Posi units for this 57-64 31 spline Pontiac Olds 9.3 rear. He sell a thick ring set of gears in 3.42 , 3.64 3.90 etc so it will fit the more common OEM 2.69. 2.87, 3.08, 3.23 ratio factory posi units. His new Posi units are also the 2 series so you can retain your original 2.69 2.87 3.08 or 3.23 if that is what you like or buy his 3.64 and his Posi and go all new. I did his 3.64 gears on my 63 Catalina recently after I found a good deal on a local 2.69 Posi (Safe t track) Pontiac rear . Check out his Ebay Store for your needs http://stores.ebay.com/Fabcraft-Meta...=p4634.c0.m322

 

There is a guy on this sight selling a new style 9.3 posi on ebay. MONZAZ

 

Yah, I am out at this time but will have 50 more at the middle to end of the month. Jim

 

Do you have pics, prices manufacturer and more info ? There are people on this site who are interested, and maybe some who might be interested.
Ralph

 

Any 29 splined units?

 

No 29 spline that was only 2 years and not really worth the effort when you can get 31 spline way stronger.

We might have an original on the shelf...Will not be cheap.

 

here is what my unit looks like installed...wow that did not sound right...lol

 

One should always have pride showing their 9.3 inches

 

geez...... I think I smell coffee... time to wake up.

 

Whats a ballpark number for the whole 31 spline 3rd member, ready to drop in a car ? You are welcome to PM me. What year 31 spline (59-64) axles can I use in a '57 housing ?
Ralph

 

all 9.3 57-64 can be interchanged with 29 or 31 spline posi units and any gear ratio.
What ratio are you looking for?

 

None of them , as far as I know .
However . Dutchman makes 31 spline axles for a '57 .
https://www.ebay.com/itm/Axle-shaft-...hX4wfC&vxp=mtr

 

is that 265.00 for one axle shaft...Woof... that is alot. I can get thenm through Moser way less money 370.00 for 2

Jim

 

IDK , the auction states $190 per axle . That's $380 per set + freight .
Yes , a pair of Mosers for $370 is a better deal .

 

I am not sure what ratio is in the '57 now. LSD didn't come out til '58. I was hoping to have two setups....... one for the highway and trips and one for "short trips" (1/4 mile or around town). I would like to use one set of axles as well as convert the existing '57 rear end to LSD. I am thinking about 4.10 to 4.56 for the short trips.


I thought I read on a thread here that stock 59-60 axles could replace the 57-58 because they were the same length. The 31 spline units are far more available.


I did check out the Dutchman site a couple weeks ago and $180 per axle is what it is. I have browsed FabCraft but haven't called them.


Another factor............. I am "building" a '64 Olds Starfire with a"warmed up" 455 and Turbo400. I could swap center sections back and forth between them.

 

What you read was wrong .
59 and up axles are longer than 57-58 . This was due to an increased tread width .
If you have a 57 or 58 you will have to use aftermarket axles with a 31 spline diff unit .

 

I would certainly be willing to use aftermarket axles when I can find a good LSD.

 

Those axles are not even the correct length for the year? also pontiac same years as Olds were always wider.
So I hope they give enough to cut the threads and then hope there is not a disclaimer on axles about cutting drilling etc will void any warranty like other axle companies...

Just trying to point out deals these companies make like a catch 22 deal... Watch out.

Jim
J D

 

Jim, I heard you were one of the "Go To" people on the subject. I knew the Pontiac "Wide Track" axles were 1" longer.
I was "hoping" to convert a 57 open to a "posi" and convert to 31 spline. Is this realistic ? I might try to send you a PM tomorrow.
Ralph

 

Jim, Do your diffs use clutches? Looks a lot different than stock posi.
Pat

 

They are not stock posi units. They are aftermarket Eaton units. They will use the clutches like the 1964 only eaton units from the past. Everything in these units are heavier duty case spiders cross shaft etc. even hub bearing diameter.

Tried to better in places we could.

The first designs were Spicer power lock units... that is a good design but spider gear teeth were kind of small and buying and or finding parts for the unit was getting expensive. We were waiting for Brad a fabcraft to build the cases for the spicer unit but it did not happen only the parts for the internals were ever made. I decided to make our own unit before the gasser craze left for another 20 years. After we got the unit running brad stuck up a deal with Auburn to finally produce a unit for them. That unit is a cone type unit which is not rebuild-able It is a good unit but I am sticking with my design I think it works well and should have longevity. I have made Detroit lockers, true tracs Power trax, all in the 9.3 form... etc. This is what I try to do...Solve problems of no parts.
We did the Buick 8.25 rear and made gears for this axle housing assembly where there was NO aftermarket support at all. We now have 3.42 3.64 gears and carriers to fit the 2.73 2.93 3.23 3.42 gears etc.
Jim
J D Race

 

Yes, It is all doable...Just always costs money for custom stuff.

We will need some measurement and discuss some other stuff to get a game plan.
ALL 57-64 can handle 29 or 31 spline units and gear ratios.
I am pretty sure the early 9.3 57 58 had different offset backing plates with smaller width shoes.
Hoping someone can confirm this I have parted out many rears, BUT for some reason I never got into measuring the shoes and backing plates for confirmation and can not find too many raw original specimens to confirm in this area.

JIm

 

Here's some information from The Hollander ;


















The spline count , the length , and factory part # of every 9.3 axle is there .

 

Charlie,
Thanks ! I can't seem to print it out tonight. My eyes are getting foggy and my concentration is dropping off. I want to study the information more closely in the morning. Maybe I can explain better later.
Ralph