Hot Rods Chevy Rear ending question

I recently bought a p case rear axle off a guy that claimed it was a 456 outta a 1962 Chevy. But it has factory leaf spring mounts and correct me if I’m wrong but would an impala be coil overs? It’s out of a model a coupe that was bought at the meltdown drags. It’s def a two wheel peeler but not positive it’s a posi or a spool. My question is how do I identify it for sure so I can order a ring and pinion to rid myself of the 456s. I don’t believe the tag is there anymore


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It can be a 62 housing that somebody cut the coil spring mounting points off and welded on leaf spring pads. Its highly unlikely that there is a spool in there. From the factory it came with a Dana Power Lok. Pictures and or casting numbers would help to identify it.

 

take it apart, post large, detailed, clear pictures, and we can help you figure it out.

 

There is a date code on the housing. The "ham" could be from a 62 ,but the axle from a 55 to 57 Chevrolet as the "hams" all interchange

 

Leaf spring mounts could have been a '62 Truck. Truck arm mounts and leaf spring mounts look the same.

 

Hey J,
From my experience with 55-58 Chevy rear axle housings in many different combinations there are ways to check. If it is a true Positraction gears and housing, there will be a definite "fishy" smell to the gear lube used. Posi gear lube oil is definitely smelly vs the stock non posi oil. The second is the old "raise the car, spin the tires, both go forward at the same time" ...test.

We used the last test on many of our friend's 55-60 Chevy cars. We also had a 56 Chevy Positraction 4:11 gears in our 40 Willys Coupe build to start. We swapped out the 58 Impala 4:56 gears for the 4:11 gears that made the best times in both cars. (Always remembering to use the smelly fish style oil made specifically for positraction gear units.) For us, Positraction does work and it does it well. Good slicks also help unless you are in a misty environment or rain.

Jnaki
If you are going to use the hot rod for the drags and street, it was handy for us to have a second 3rd member already loaded with 4:11 gears for an easy swap, prior to long distance cruises. 4:56 gears are only for the drags, not long distance driving. If you have a 3:55 or 3:78 gears, that is better for long distance. But, not so much at the drags.

 

truck rear ends and car rear ends were quite different...the truck has a round center, the car is oval shaped. And trucks had coils in back starting in 1960.

 

Corvettes had leaf spring rear axle housings thru 1962.
My understanding is (but i'm not certain) they are the same width as the 55-57 Chevy's

Movin/on

 

Thanks all, I’m working but when I get home I snap some pics of the numbers. The tires def soon in both directions when spin forward.


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snap pics of the entire rear end, also.

 

looks like it's probably a 55-57 housing, the leaf spring perches look original.

As mentioned, it's very common to have a different center section swapped in, especially in a hot rod.

 

^^^^^ 10 model years worth of interchange.

 

Your current ladder bar set up is not going to be very pleasant on the street. If one wheel hits a bump, the parallel ladder bars will act like a big giant anti-roll bar. Your best bet is make new brackets to angle the bars towards the center of the car and use heim joints at the rear and rubber bushings in the front.

Kind of like this


-Abone.

 

Didn't the real positrac pumpkin housing have a P cast in it ? 1957 housing will have a drain plug in the bottom also.
Corvette I'm thinking is same width.

 

You seriously need to know the EXACT year of the HOUSING when it comes to axles and axle bearings; 55-56 are the same, 57 is all by itself, 58 on are mostly the same regarding axles/bearings. There are also some minor differences in the THIRD MEMBERS, but basically, 55-64 full size cars, 62-63 Chevy II/Nova, and 56-62 Corvettes are all interchangeable. But, stay away from the early Chevy II/Nova third members as they use a thinner casing and smaller bearings. It does look like a "P" case, if my eyes are't deceving me. With the 4.56 gears, you'll need to know what series the carrier is when it comes to changing to more street friendly gears; it can get confusing in regards to gear spacers, thick or thin ring gears, and solving those issues. I'm going to guess your housing is a 55-56, but if it has a drain plug, then it's a 57. The stock spring pads are only spot welded to the housing with 3 spot welds on each side of the spring pad (total of 6 spot welds). Only reason I say that is, they could have been added by someone, and would then most likely have full weld beads on the pads. Axle bearings will have ID numbers on them; that will help you figure out exactly what you have. The Corvette's are the same width. DZAUTO over on ChevyTalk.Org is the true guru on these rears, and he will gladly answer PM's from anyone. Tom Ordway is another member there with extensive knowledge of them. I am Butch/56sedandelivery

 

The trucks had a trailing arm suspension starting in '60 ( uh I think). The rear mounted to the trailing arm and had spring pads along the same lines as a car with leaf springs. The coils mounted to the trailing arms not the rear end housing.

Now this is a Jim question??????. I do not know what year the truck stopped using the drop out chuck and went to a more contemporary GM rear. My '65 had a 12 bolt and not a drop out chuck. Do you recall what year they changed over? Was it '65 or earlier?

 

63 was the first year for the truck 12 bolt rear. The drop out third member was used through 1962.