Projects 1949 Oldsmobile rear end question

Good afternoon everyone, so I finally got started on my Oldsmobile, I ended up using a 1969 nova sub-frame, narrowed 2.5 inches, it will be traditional except for the suspension and air ride. I have a 283/glide combo for it. Now I have a real question and please no smart**** one liners from the 10 thousand post new crew.
I have a 57 ford 9 inch, and a 1956 passenger rear end, yes I have measured and done research, I was hoping for a good fitting later rear end that would be easier to find parts for. Has anyone used a different rear end with a good fit and yes it will be low but not laying frame. I dropped in a picture from a month ago before it went into the shop.
Thanks in advance for any good advice. James

 

genuine questions here not being a smart*****.

What's wrong with the original? You mention about parts availability, does it need much to make it serviceable? Reason being you know it fits and works and you have it. Kanter/Fusick or eBay will have wheel cylinders, shoes and drums and bearings.

Do you know the width? you mention a 57 9" aren't they about 57" wide? what about a customline rear from 49-54 they were 57 1/4" wide and take stock ford backing plates and hardware which will help with parts if thats a concern.

I have a
'55 olds with a 455 in it. I got hold of a 9" in a swap to put in the car, but the original rear is holding up well, so I have decided not to put the 9" in - if it's not broke...

Most of the cars became wider not long into the 50's so you might find that rear ends available to you are not that much younger than what you have.

I can't imagine the 283 would cause that rear too much concern.

 

i have over ten thousand posts , but i promise i will not be a smart****

i'm no real help.....but since you have a chevy front suspension , i'd be looking at maybe a 70's Camaro or Nova rear end to keep the same bolt pattern. i'm sure something like that may be the correct width...others will know more

 

Howdy neighbor, you got any idea what rims you will run? If you know the offsets you can find an axle that will fit the car and tuck the rubber at the same time. Also, spring perches or you going coil overs? I have an Olds posi under my 68 442 with a W-27 aluminum cover on it that would look pretty cool under your car. They aren't impossible to find, easy to work on. I even found hardened axles for mine after I rag dolled a set at PIR, Supercars in Tualitin has tons of Olds muscle car parts. Find you dimensions and spring requirements, grab your tape measure and head to All American Auto Wrecking in the couve. Another excellent resource is 6 States over on Columbia, he has built a lot of rear ends for me over there.

 

The 49 and 50 use "nascar" type rear trailing arms. There are brackets welded to the top and bottom of the axle tubes that need to be swapped onto the donor rear. Those brackets have special rubber biscuits, but it may be something you can make from some other rubber thing.

That might be a 3.60 ratio, not sure...because your car may be the 6 or an 8...and different ratios were optional on each. There is an "Olds Pontiac" rear end thread here somewhere, to tell how many years of center chucks will fit that housing, and what ratios.

mid 50s Olds rears I use are about 59.5" flange to flange. They have many ratios; I have 3.08, 3.23 and 3.42 on my cars. I just don't think these chucks would fit, but I could be totally wrong.

If it were me, I'd check the ratio on yours first. If it is ok for todays speeds, I'd run it, as they have good brakes/axles etc. Autozone had my 55 shoes in stock! Jack up one rear wheel only, then chalk mark on that tire, and a mark on driveshaft. Now slowly rotate that tire precisely TWO turns while counting driveshaft turns. If it turns 3, you have a 3.00-ish ratio...like 3.08. if it turns just under 3-1/2, then it is 3.42, etc etc

 

Thanks all for the input, the reason I am thinking of changing is the pinion seal is leaking, the brakes are bad, cylinders also. And they have a crazy lever action shocks built into the backing plates. I am no stranger to modifying for new shock mounts, but who knows how good the axle bearings are, this thing could cost me a grand when done. I love the rear suspension set up I plan on keeping it, reminds me of 60s Chevrolet trucks which I use all the time on bagged 40s cars cross-member and all. Also for the record no knock on a lot of posts but I grow weary of thousands of posts in a few months with the same old get a tape and go to the wrecking yard,use the search, worked for 100 years why change it bro. Thanks again I am checking parts prices and ratios as it was a six auto it should be a high ratio.

 

I've done several Oldsmobile rear axle swaps over the years. Your Olds is a 98 series isn't it? Your 9" should fit, if anything it will be too narrow (or is it a truck rear?), you didn't say what passenger rear the 56 is, if it's Olds it should go as well. I've used Nova/ Camaro rears under them, fit well and are easy to come by, least the 10 bolts are, (fine for your app). It still will fit if your Olds is a 88 or 76 series but you might have issues if you run skirts, I've had custom offset rims made to run skirts. Like someone else said if you use the 10 bolt your bolt patterns will match.

 

I used a 9" out of a 60-64 full size Ford passenger car under my '50 - 88 Coupe, transferring the brackets to fit as original. As I remember it measured 60-61 inches overall width. Using the stock rear arms, you will want to move the axle center-line forward at least 1/2" to center the tire in the opening, at ride height.

 

You might check my thread on my 49 Buick Sedanette build. It has pictures, description of installation and ID of rear I used.