3.27 gears for flathead v8

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draggin49

Senior Member
Hello,
I have a 1932 Ford roadster that is currently stock motor/trans/rear end.

I recently picked up an original Edelbrock Slingshot intake and will also be buying a set of aluminum heads , headers so that should pick up a little more HP

My car does not have fenders or bumpers so it is a fair bit lighter than what it would weigh off the assembly line.

I plan on daily driving this car and where I live that requires going on the freeway regularly . My car can’t currently do this , I believe I have 4.11 so doing 65mph would be way too many rpms , I have 27.5” firestone black walls on 1940s ford steel wheels. The car won’t do much driving on hills . 1st gear is super low , gotta shift to second really quick.
I was curious if these gears would work for what I’m trying to do.
Or do I need to wait and save up for a Columbia OD?

Kind of unsure which way to go . Not sure where the OD on the Columbia would get me rpm wise . I figure there may be some who have or know people running the Columbia units
 
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Considering the amount of money spent on a Columbia installation you might want to check out the Mitchell overdrive unit as an option.
 
I did stumble across this as well, it looks like you can retain the original banjo housing but upgrade to much stronger axles/internals .

http://www.hotrodworks.com/product/model-a-1932-ford-axle-conversion/


It requires 1940’s ford /Lincoln hydraulic brakes & backing plates which I just had a custom set for front &rear made for my roadster.

Although it may be overkill unless I go to a blown flathead where it’s making a significant amount of HP/tq to really start being hard on the trans/rear end
 
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To give you an opinion on your question, I have a 37 Ford (relatively stock) with a 4.11 rear end and Columbia. When in overdrive, the gearing is slightly under 3.0. I can easily start on level ground when in overdrive and have for over 20,000 miles without clutch change. If it looks like a slope, I need to get out of overdrive (before stopping). With your light weight and expected 3.27 gearing, I would think you can start from some slopes with ease, but not from a dead start on a good sized hill (5% grade?). I'm sure others will disagree.

I also have a 39 Ford with 3.54 gears. It easily starts from a dead stop on any Iowa hill I have been on. Both cars are a lot heavier than yours.
 
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If it was me I would put in a set of 354's. It should keep up with L.A. traffic with the tall tires in the back and not over wind the motor. The Mitchell Overdrive would be the next best option in my opinion.
 
I have 3.25 gears in a 30 roadster. I also have the low first and second gears in transmission. I also have a mild cam with good low end torque. I am very happy with it. I like to drive 55-60 and it is perfect. Goes 70 with ease. Hills have never been a problem.

John
 
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3.78 gears in my '41 put cruise rpm on the interstate up around 2900, which is loud and uneconomical. Considered the cost of both Columbia and Mitchell as too high. I switched to 3.27 gears from VanPelt and now cruise rpm is down around 2300 which sounds much less busy and mileage went up to 17 mpg. Tried the gears in Staunton VA, which is very hilly, and had no problem starting on some pretty steep grades.

Note that I have a big inch (284) engine with Offy heads and exhaust headers, which make it quite strong on the low end. But your roadster is much lighter, so I expect you will find similar results with a stock engine.
 
What tires are you running & at what mph? I get different numbers.

Using 27 inch tires, 3.78 gears & 60 mph I get 2822 rpm
Using 27 inch tires, 3.27 gears & 60 mph I get 2442 rpm
 
A T5 overdrive trans and a rear gear from 3.7 to 3.9 will get you in the ball park. Aim for about 2250 rpm at 60 mph. Hope you have converted to Hydraulic brakes.
 
Ive never been able to go very fast on the Southern California freeways. Too much traffic. Id worry more about overheating while sitting still on the freeway. Just my 2 cents...
 
JSeery said:
What tires are you running & at what mph? I get different numbers.

Using 27 inch tires, 3.78 gears & 60 mph I get 2822 rpm
Using 27 inch tires, 3.27 gears & 60 mph I get 2442 rpm
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Did any 1932 fords have 4.11 gears stock?? My gears feel super low.

I am running 16x4.5” rims in back with Firestone 16x650 I think they are around 27.5” tire size

Fronts are 16x4” rims with 16x600 Firestone’s
Those may be a tad closer to 27”

Wheels are off a 1940’s ford . I just had custom hydraulic brakes from 1940’s ford cores made for the front and the rear to increase the stopping power
 
After loggingin this site still dumps my message as not having been. Not typing all that reply again until...
 
Fred,

Sorry for the hassle. That problem happens when your browser is out of memory. Here is how you can beat it:

1. Clear the cache and temporary internet files from your browsers memory.

2. Next time you login, click the "remember me" box.

After that, you will be good to go!

Thanks,
 
Tim Brown said:
Ive never been able to go very fast on the Southern California freeways. Too much traffic. Id worry more about overheating while sitting still on the freeway. Just my 2 cents...
Click to expand...

In reference to the staying cool part . What are the key factors to keep it cool?
Is there any newer radiators that have more rows that can fit in place of the original ?? Maybe newer style water pumps with upgraded impellers ?

Not sure if the stock radiator/water pumps can be reused but modified to be more efficient ?
We do get hot weather in the summer so a good cooling system is money well spent
 
I'm no expert but I have run tall tires with 4:11 rears
in several cars with 40-100 HP. Gets more top end at
lower revs.
Try putting a set of Firestone or BF Goodrich 7-50-16s on the rear.
they are over 31 inches tall. That will get your top
speed up and your rpms down without shelling out for an OD.
(Make sure your brakes are good!)
For around $500, or less if you can find some used ones,
you might be surprised! If you don't get the results you want
they are easy to sell!
Good luck!
 
Tony Martino said:
I'm no expert but I have run tall tires with 4:11 rears
in several cars with 40-100 HP. Gets more top end at
lower revs.
Try putting a set of Firestone or BF Goodrich 7-50-16s on the rear.
they are over 31 inches tall. That will get your top
speed up and your rpms down without shelling out for an OD.
(Make sure your brakes are good!)
For around $500, or less if you can find some used ones,
you might be surprised! If you don't get the results you want
they are easy to sell!
Good luck!
Click to expand...

Tony what rim size did you use to run the 750x16s ?

I believe I have 4.5” in the rear . If I need to go larger I can find new ones
 
I used '35 wires several times, and also '41-'48 solids.
Coker will tell you the rims aren't wide enough but they have been
used since the '50s and probably before. I ran several sets on my
former '31 on a '32 frame, (avitar). '41 wheels are 4-1/2 and can work
fine. Run tubes of course!
Here is an old shot from '07 with 7-50-16 'Stones on the rear.
First ones I ran.
 

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Nice looking ride you’ve got there! Sounds good I’m gonna order some 750x16’s and I will keep the old tires as spares that can go on the front .
 
I have overdrive in my heavyweight(with me on board) 1940 sedan. Still I would like to have the 3:25 rear gears. Yes, my engine is slightly modified but I sometimes forget to exit overdrive and have no problem starting from a STOP sign. The 3:25 would be great for overdrive cruising down the highway. But, not for drag racing.
 
JWL said:
I have overdrive in my heavyweight(with me on board) 1940 sedan. Still I would like to have the 3:25 rear gears. Yes, my engine is slightly modified but I sometimes forget to exit overdrive and have no problem starting from a STOP sign. The 3:25 would be great for overdrive cruising down the highway. But, not for drag racing.
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Yeah my original flathead v8 with speed parts isn’t gonna make huge power or see any drag racing , so I think itll be worth doing the 3.27s
Thinking about selling my daily driver and just driving my roadster
 
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