Technical 39 Box with Zephyr gears What rear end ratio?

Think about 39-40 fords were a lot heavier than a 32 and most of them came with 3.78 ratio. I think you'll be fine with your hot rod motor. I just switched my 40 rear end over to a 3.54 because I have a sbc hooked to the OG driveline.

 

I have 25's and 3,78 rear. It is a stock looking 32 5W. I have a 274 with a Max 1 cam and a wcfb . it pulls great . I have a very steep driveway and it goes right up in second. I have a 3.54 set to go in and maybe a 3.25 later. The engine has a bunch of torque and it wants higher gearing.

 

Running and driving in a rod? Stashed in the attic? Or just Volvo boxes?

 

Thanks for posting the photo Bob. Never noticed the Model A rear crossmember center section added to the '32 rear before in Doans chassis. Bob

 

That is a neat setup!

 

Volvo overdrives, stashed

 

To change to 3.78 not worth the effort, only amounts to around 200 rpm less at 60 mph..3.54 would be around 400 less at 60 mph...Respectively at 30 mph it would be 100 and 200..In first gear at 10 mph the difference between 3.54 and 4.11 is only about 165 rpm!! Piece of cake for your engine/car weight..!!..

 

Good idea, looking forward to se it used [emoji6][emoji3]

 

After all this I think if the condition of the 4:11's are good I will leave it alone. If they look bad and need replacing anyway, then 3:78's. I am going up to 750's on the rear tires at some point as well. Thanks to everyone for chiming in!

 

i put together this late `32 rear axle with a Columbia for a `32 roadster project. the motor is a full house 276, 26 tooth cluster, 3.78 ring & pinion, 7.00 x 16" tire.

i`m using the same rear end/tires in my `37 1/2 ton with a 239" engine, 28 tooth cluster. it will cruise all day @ 70 mph, and around town it will accelerate smoothly from a stop even when it`s on the high side. bottom line i would find a Columbia for your car, those square box Volvo units don`t belong in a car like yours.
tom

 

Agree!

 

If you're going to switch to 750's, borrow a set NOW and run them to compare before you even check your existing gears. Just a thought. Bob

 

Good thought! Thanks

 

the square box isn't anything to do with Volvos...

 

Put 7:50's on the rear and it made a noticeable difference on top end. May just leave the 4:11's.
The extra rake aint bad either!

 

How much in rpm?

 

and that will split the difference between your original setup and 3.78s with the original tires... cheaper than the QC or OD option too...

 

At 60 mph I am about 2,500 RPM That is using a GPS since my speedo is off a bit.

 

My computations come out that the tires are 33" plus...31" and 3.78 comes close to 2500..Just my doodles...

 

I have 4:11's now so there you go!

 

What meant was are the tires 33" and my doodles are right?

 

I ran a '39 box with Zephyr gears and a 3:78 in my '30 roadster behind a 324 Olds, worked very well, didn't accelerate as quick as it might have with 4:11 but wound out more in 2nd gear. If I had been street racing, which is illegal and dangerous, so of course I didn't, but if I did, I would get beat off the line but often passed the guy I wasn't racing while still in 2nd gear...