1957 Ford 9" rear end

[oneoldtruckguy]

Thinking about putting a 9" rear end in my 1950 F1. I found a nice 9" rear end out of a 1957 Ford pass. car with an automatic. Does anyone know what the rear end ratio options were in this car? I have a 3.78 or close now but would like to go higher for more road speed and lower rpm. I am in the process of changing from a 4 speed to a rebuilt 3 speed top loader also.

[ponymare]

Most likely it would be 3.00, but to use a car rear end, the spring mounting pads will need to be welded on the other side, and maybe moved farther apart.

[craig]

Depends on what engine the car had. I had a 6 with a straight stick that had 3.89's, a 292 with fordo that had 3.23's and another with 3.10's behind a 312 with fordo.

Lock up one axle, turn the free axle, count the pinion revolutions and figure the ratio

[5851a]

If you use a housing from a pickup with a 9 inch before 1973 it should be the same width and bolt in. I think from 73 to 86 will bolt in but be wider.

[roadster36]

I have used quite of few of the '57 rear-end's in various projects. Almost all had the 3:89's as previously posted by Craig. They work good with a T-5.

[paul2748]

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57 Automatic rears had around a 3.20 something or possibly a 3.10. The standard and O/d trans' had lower ratios (higher numericaly)

[Ford blue blood]

The 300 Custom I parted (rusted in half) had a 3.56, it was a factory air car with a 292/auto. My Ranchero has a 3.56 also, it was a 292/manual, and my Retractable is a 292/auto with a 3.56 as well. A Ranchwagon I had was a 6/manual with a 3.89.

[WestCoast]

rear ratios run from 2:50 to 4:30, basically the only difference in the rears is some had 31 splines and some had 28 axle splines, the 31 spline axles can be shortened, there should be a tag on the rear housing having the ratio info , what ratio do you want? 3:50, 3:25, 3:00, 2:75, 2:50, these are all auto,trans rear ratio's, take a pretty stout engine to run one of these, well maybe not the 3:50 or 3:25

[Alaska Jim]

It all depends on the transmission gear ratios, as to what rear ratio will work best, this applies to automatics as well as manual transmissions. that is why there are so many different ratios. not all automatic's or manual are the same ratio in every gear.--Jim

[Ole Don]

If you have to go out and spend money for a three speed, think about spending a bit more and look in to a five speed. They are Soooo, nice.

[WestCoast]

Jim, auto trans have a lot of different gear ratio's in the lower gears, but they all have 1 to 1 final drive, except the over drive trans

[Alaska Jim]

Yes, that is true. thanks for clarifying that.

[GreenMonster48]

1957-72 Ford 1/2 ton pickup rear ends are basically a bolt in to the 1948-52 F-1s. I'd hold out for one of those. They're still plentiful and offer a wide range of ratios and have the same wheel bolt pattern.

[WestCoast]

in my experience the p/u rear ratios were kinda low, 3:73 or close to that, 4 wheel drives were even lower

[GreenMonster48]

I've seen a bunch of 302 powered F100's with 3.25 ratios. You're right though, you could probably run through a field of 3.70's before finding a tall one.

[hardlyrider]

Here is a link with some info that might help you identify the ratio if that rear end was the original in the '57.

http://1957ford.com/asp/gallery.aspx...=1&catdetid=29

[George/Maine]

The truck rearend would be better 57 to 72 the car length is about 4" short ,not wide enough.