Technical ford 9 3/8s gear change

I have a ford 9 3/8s pumkin or chunk . Trying to find a different ratio. Does any gear companies make ring and pinions for this unit

 

A regular 9-inch center will swap in. The 9-3/8 is not much parts availability. Just buy a regular 9-inch third member all set up with the gear ratio you want. I think all 9-3/8 were 28 spline, but verify yours and just get the new third member the same spline count.

 

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I don't believe there was very much aftermarket support for these, at least ring and pinion wise, I was given a couple complete rearends in the 80's, I had never heard of the 9&3/8 units, thought they were nine inch rears, pretty sure they had a gear ratio in the 2.55 range, I think Ford originally installed them in big cars like Thunderbirds and Lincolns.

 

I put a regular 9 inch center section in the one I had

 

I ended up with one from when I worked as a CoOp student at a brake manufacturing company in the Detroit area as a CoOp student. We needed parts to make a fixture for the brake dyno, so the Ford engineer we were working with stopped at the axle plant (Sterling Axle?) and picked up an entire rear. We chopped the ends off to make a fixture, and my boss let me have the rest
I carted that sucker around for a good ten years through several moves before I finally gave it to a coworker.

Only they did we figure out that it was a relatively worthless 9 3/8, and not a 9”.

 

Yep, I have one for my '27 Touring (avatar). 9" center section is the only way to utilize the 9 3/8 housing.
This is a heavy monster; but very string and has Disc Brakes.

Happy Hot Rodding.

VR&C.

 

I had a 9 3/8 with 3.73 gears back in the early 70's.

 

I think the 9-3/8 were all 31 spline, four pinion at least don't know if any type of posi, police galaxy's, station wagons, t birds and probably Lincolns.

 

Sounds like truck gearing, I've never heard of any 9&3/8" used in hi-perf Fords, it would make more sense to me for Ford to have used them in trucks, but always heard of them using sub 3.00 gears in the big cars.

 

Gray iron housing , swap it all for 9 inch stuff and never look back

 

They were in Lincolns in the late 60's/early 70's. Most of the Lincolns had 3.00:1 ratios. I'm just saying that at one time other ratios were available.

 

the mid 70s lincoln I had ran 2.47 gears. Low tech overdrive.

 

Mine came out of a 70's t-bird, nice big finned rear drums, don't remember what gear it came width stock