My involvement with the Olds/Pontiac rearends stem from drag racing starting in the early 70's, the 57-64 versions were pretty much the standard rear for higher hp cars before the wide use of Ford nine inch rears, your application may not require that, the bigger issue nowadays would seem to be the availability of replacement parts.
I dont know if 56 has not the same parts inside as the 57 and up ( maybe not ) as Fabcraft say 9.3” ( 57-64 ) and to them is parts to get. I guess I need find a 57 then.
the rear end on the chain is not Olds. It is a 1935 LaSalle rear axle, look at the big nut holding the rear drum hub on. I don't know what your car needs for a strong rear axle, but most people don't recall that the 1956 and older Olds rear ends were more desirable than the 1957 up in certain smaller drag racing classes. Probably because of lower weight? One famous company or person even made a magnesium center section for the older Olds rears for those classes. Maybe Mickey Thompson? I forgot I can't see how you could ruin the early gears unless you used a top fuel dragster engine. IMO I run a stock width 55-56 Olds rear in a 32 full fender, but I had to use 56 Olds wheels that have the maximum amount of backspace of all the Olds wheels, so that I could get the 7:60x15 tires fitting inside the fenders. Also, I see no need for posi, mine spins both skinny bias ply tires equally, every time. No idea why, but it's not posi. I run the common Hydramatic gear ratio of 3:24 which is perfect for my secondary roads here. I pulled out the 3:42 Standard shift ratio because the 3:24 is better for my driving conditions.
I'm running an Olds rear in this car. They are wide, a lot of guys narrow them. I don't like the clinched butt-cheeks look of the rear tires hugging the body so I left it stock width and got wheels with the proper offset so they aren't sticking out any more than they really have to. Olds or 9", both are a good choice. www.ironandsteele.com
I have a Olds rear in my 57 Vette . Its currently got 2.56 gears for the high way and I have a 4.11 posi pumpkin as well as a 5;13 set up with a spool . parts are out there . I saw a posi center section with good gears at Jefferson this year for $700 . Id wager one could stick it in and run it jsut fine as is . guys need ot be aware the early rears had courser spline axles than the stuff a bit later until they quit making them . I believe 57 is different form 63 for example. Unless you have some serious HP your not likely to break one and if the bearings are good they will run likely longer than the owner .
F&J, thanks bring this in, do you has pictures of that 56 axle in the 32 ? So they are ’smaller’ and weight less than the 57. So the stick versions had 3.54, might be hard to find. Irionandsteel, that’s a cool car and what Hemi is used ? I’m also into has black valvecovers. You said Olds axle, is that 57 ? When youre out cruzing what gears do it like and transmission in that 3W. Saw Instagram and I been up in that area in Portland allot on trips before, nice.
Found a YouTube video of it driving by the camera guy at around 7:50 minute mark. At least you can see the tires don't stick out, and a glimpse of the rear center housing... If the video link works here.
Howdy @3w Hank, Hopefully @Ryan doesn't object to the style of my newest build, which has a 1957 Olds rear (with a 3.23 ratio and a 5-speed manual in it). I left the housing the stock width, but if I did it again I would narrow it 2 or 3 inches to try and suck the steelies in a little closer. Anyways, here's some pictures to show the relation of the tires to the body, etc..
Great, now one see the big boy.. As I was into use the 32 spring/rearcross. Is it the Olds brakes or Ford 40 ?
The chassis has a semi-flattened 1935-40 rear crossmember and spring in the rear. Rear brakes are stock '57 Oldsmobile. Front brakes are 1953-56 F-100.