COLUMBIA with 3.78 gears

[motordr]

I would like to hear from anyone that is running a Columbia with 3.78 gears. How do you like it? I am thinking of this for a 32 3 window with a healthy 265 flathead, but with stock wheels and tire size. I have a 4.11 Columbia in my other car and am thinking of going up a step in the gear ratio for this one. Looking for your actual experience on this setup. Thanks!

[Pete]

I have done that with a 296 in a 32 coupe.
I didn't like it.

[Dave/Green Bay]

Pete:
What didn't you like about it?
Thanks Dave/Green Bay

[PeterC]

Originally Posted by motordr

I would like to hear from anyone that is running a Columbia with 3.78 gears. How do you like it? I am thinking of this for a 32 3 window with a healthy 265 flathead, but with stock wheels and tire size. I have a 4.11 Columbia in my other car and am thinking of going up a step in the gear ratio for this one. Looking for your actual experience on this setup. Thanks!

Just a comment to consider in your thinking .. Flywheel should be a factor as well - I have a strong 284cu (supercharged) with 4:11 and Columbia with an aluminum flywheel. I my case the 4:11 is great for around town performance and easy launch with the benefit of the 2:97:1 high for lower (28.5% reduction) in RPM at 65mph. I am happy with this combo with the lighter flywheel.

[JSeery]

I would think that the 4:11 gearing would be the better selection. As everyone (so far) is saying good option for both in town and highway. Unless you drive almost exclusively on the highway at high speeds on fairly flat ground not sure why you would want a higher rear end gear when you have an OD.

[Pete]

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Originally Posted by Dave/Green Bay

Pete:
What didn't you like about it?
Thanks Dave/Green Bay

It was geared too tall for passing in direct high.

[Kube]

Originally Posted by motordr

I would like to hear from anyone that is running a Columbia with 3.78 gears. How do you like it? I am thinking of this for a 32 3 window with a healthy 265 flathead, but with stock wheels and tire size. I have a 4.11 Columbia in my other car and am thinking of going up a step in the gear ratio for this one. Looking for your actual experience on this setup. Thanks!

I have installed more Columbia's than I care to recall. The best overall performance in my opinion was attained when coupled to the 3:78.

[jimTN]

Its gonna depend on where you live, flatland or mtns, urban driving or country.

[hotcoupe]

i have a Columbia in my `37 1/2 ton with a 22 lb. flywheel on a 239 c.i. motor, single 94 with a Max-1 and a 28 tooth cluster and a 3:78 r&p with 7.00 x 16". and after 4,000 miles, i wouldn`t change a thing. and i know my next statement is going to get a response . . . # 41 jets in the carb. blast away!
tom

[Kube]

Originally Posted by jimTN

Its gonna depend on where you live, flatland or mtns, urban driving or country.

Good point... around here, lots of hills. None too steep but many are very long.

[Don]

3.78 in my 35 roadster Works greatin hills and on highway

[supereal]

My '47 convertible has a 3:78 rear, and an overdrive with a 33 percent reduction. it is fine above 45 mph, but lugs below that. It will run at hiway speeds of 60 to 70 mph, which pushes the stock handling and braking to limit. What you select must be based on the intended use, lots of hiway, or mostly city, because the balnce is tricky to reach.

[Kahuna]

I didn't know what a Columbia O/D reduction was? It has quite a drop in RPM.

[Highboy34]

27% reduction as I remember.

[PeterC]

Originally Posted by Kahuna

I didn't know what a Columbia O/D reduction was? It has quite a drop in RPM.

per Columbia literature - 28.5% reduction

[Bob G/Spanaway]

I have had 3.78/Columbia in both my coupe and PU for around 10 years.
Just '040 over 239 with dual 97's, heads and mild cams.
They work great in all kinds of driving.
Wouldn't change a thing...except maybe the 25 tooth Zephyrs in my coupe.

[Kahuna]

PeterC
What is your rear tire size? Diameter?
On my 32, I have a Gear Vendors O/D that reduces the final ratio from 4.11 to 3.21.
My tires are 29 to 29 1/2" tall.
In O/D at 65 mph, my engine turns about 2300 rpm. Wondered what yours is?
Thanks,
Jim

[48 coupe]

My 48 has 3.78 columbia max 1 cam 259 ci. offey heads. 2 ecg carbs. 51 jets. light flywheel. pulls good. I think it's a good set up.

[PeterC]

Originally Posted by Kahuna

PeterC
What is your rear tire size? Diameter?
On my 32, I have a Gear Vendors O/D that reduces the final ratio from 4.11 to 3.21.
My tires are 29 to 29 1/2" tall.
In O/D at 65 mph, my engine turns about 2300 rpm. Wondered what yours is?
Thanks,
Jim

Rear tire diameter looks like 30" to me - Tire is Coker Firestone bias 700 X16 - I do not have a tach but guess is 2300 rpm sound reasonable.

[38 coupe]

There have been so many discussions about rear axle gear ratios and overdrive that I put together a spreadsheet showing the most discussed combinations. I set the color bands based on my driving experiences with a 3.78 axle, no overdrive car. Obviously other people will have different opinions about comfortable rpm ranges. These calculations are accurate for 1:1 ratio in the transmission and a 28 inch tall rear tire.
I hope this image is readable.