55-64 Chevy gear ratio ?

Was there anything taller than 3:08s

 

3.08 was "it" as far as I know and I've had a bunch of 'em. THey used overdrive transmssions with the 4.11's to get power and road speed, but 70 mph in those days was IT for speed limits and cruising speeds. Now we "cruise" at 80+!

 

2.73 sticks in my mind--behind a P/glide, I think.

 

For tri-fives, the Danchuck catalog I have shows 3.36:1 with a PG as the highest.

 

3:08 3:36 3:55 3:70 4:11 4:56 are the factory gears available for the '55-64 car rearends.

 

Thanks guys, was hoping for a tall gear for a long run.

 

Snarl is absolutely correct----but I think the 4:11/4:56 ratio's had to have a different housing because of the overall size. I stand to be corrected on this since I've never had one.
cooger

 

The 2.73's didn't come along until around 1970.

 

Not so...any of those ratios, including Posi, and including the 5:13 ratio not mentioned above, would fit inside the stock rearend...I've had several '57 rearends in various cars of mine (still have one in my '40 Stude) and once owned a '64 Impala (built 301", 4-speed and a 5:13 rear end), on the street...FWIW, you can read about that car in my second book "Fast Cars, 4-speeds & Fist-fights" ...

R-

 

I had a 56 hdtp with a 355 three two's and a four speed. It had a 3.08 rear in it and would cruise 80 all day on interstate. Best cruiser I ever had. Lippy

 

3.08 gear in my 32 ford, cruise 80 mph,3100 rpm. Rear tire 255/50/17 27.09 tall

 

The pumpkin is different on the 370 411 & 456 The housings will take all rear-end ratios. If you put a factory posi in a 55 -56 the axles need shortened a little...

 

There are different carriers for the 4 series gears and the 3 series gears. You can safely put 3 series gears in a 4 series carrier with a custom machined spacer but not vice-versa. The 4 series ring gear is thicker than the 3 series, hence the spacer.
I run a set of Yukon 3.55's and an Eaton posi in a 57 (stronger than the 55 and 56) center section, in a 55 housing. There's a gusset in the open diff center sections that needs to be knocked down to run any posi unit. Posi carriers will have a P stamped on them, opens will not. My car was an original V8 Powerglide car, and it had a open 3.08 rear. I swapped a 3.36 complete center section in, grenaded it, and swapped to the 57 piece.

 

I'm currently running 3:55s and there great for 120 mile round trips and street driving. Just need taller gears for long trips. Thanks for all the examples but I do know how to calculate RPM @ MPH useing rmp x tire dia. over gear ratio X 336. My ? was a simple one. Is there anything taller ?

 

3:08 is the tallest.

 

Hey there Bosco,
Could you give me some more detail about your comment in shortening the axles if installing a factory posi?
I have a stock '55 rear end with an open unit and would like to swap that for a posi center section. What would I need to do in order to install that?

thanks

 

what you need is my 5.38 and a OD then you get both worlds.And the 5.38 fits in a regular housing

 

If you use an Eaton posi, you will not have to shorten the axles.

 

Nice hi-jack.....what he needs is my 4:56 W/Posi ...lol

 

I have a set of 2.73s out of a 62 Nova that was a 6 cylinder powerglide car. We swapped them in my Dad's 56 because he was tired of the 3.70s.

 

5:38s , even with an OD no thanks . I've got 4:11s with a posi and 4:56s with old school locking spiders sitting on the shelf ready to go at a moments notice .

 

There are no stock 2:73's available for the '62 nova with drop out center section. The later Salisbury rears did.
If there really is any 2:73's for the drop out rears, it would have to be obsolete aftermarket...

 

Ok, since everyone likes talking rear so much. I'm just gonna get a peg leg flyier for the 57 Poncho I have also. Now there you can find some putt putt gears.

 

my 59 brookwood 283 powerglide had a 2.73 open rear

 

There two cases but the housing are the same.

 

i've owned a 56 chevy for 40 years(yes really) and 3:08 is all i have ever found.also have a 59 el ky for 25 years.3:08 is th highest ratio i have ever found.don't mean thats it,but all i have found or read about. my.02

 

4:11 in stock case .

 

To clarify, 3.08 was the tallest gear available from the factory from 1955 to 1964. There very well may be some aftermarket sets taller, but none that came off the showroom floor.

What I'd like is a definative list of what gears would be found where....I know I've taken 3.08's out of a 1960 V8/PG car, the next time I went looking, I found a 1962 V8/PG car, and it had 3.36's in it.....I was hoping for 3.08's, but I guess they'll have to do.

 

Here is a listing '58 through '64 rears available: http://www.348-409.com/differential.html

The pumpkins were interchangable from '55 to '64, but the '57 through '64 have heavier webbing.

 

^^^^^ Great chart, I put that in the keep file.