3.23 or 3.55, this is the question

[AR67GTX]

I once ( in the 70s) had a Trans Am, 4-speed with a lightly built motor that I put a 3.73 in. I had something like 255 or 275/60s on the rear at the time. I remember believing back then that this is a perfect rear gear ratio. Strong acceleration, drive lower speeds in any gear. Didn’t seem to buzzy or stressed on the highway. But that was with a 4-speed. My 67 GTX is an auto with a little higher than stock - stall converter. Its a little busy on even 60 mph roads and if I did any serious highway driving I would not go numerically higher than a 3.55 with an auto and non-stock converter. But that’s just me at 71 now.

 

[Cranky]

It only took 14 post to ask the right question.

so how tall are the rear tires?

2.9 to 3.2 is a big change. If this 440 runs good the tires will spin just fine with 3.23’s, and you can still go someplace on the freeway.

Tire height is one of the first things that should be considered and I agree with the comment that a 440's power should be enough to even light up the tires with a 3.23 and even better with a 2.94. That gear was plenty enough even with my 330horse 383 that was in my 70 Challenger and it allowed the car to cruise easy enough at 80 and better.

 

[Darter6]

Do you guys have more than one you swap out?

At one time I had every 8 3/4 ratio (Factory and Aftermarket) from 2.76 to 5.13. I would drive my Duster from Pittsburgh to Denver with 2.94 then swap to 3.91 when I got there.
Did that while going to school in Denver when we had breaks every 4 months. Oh to be young !

At least in my 17 year old brain in my 55 year old head

My fathers favorite saying. "I've a 18 year old brain stuck in a 80 year old body !"

 

[gtx6970]

Both my cars have a 245-60-15 tire.
383, auto and 3.91s This car is A LOT of fun around town. But hiway driving any measurable distance is NOT fun.
2nd car is hemi auto and a 3.54 Dana. and is noticeably better on the hiway which is surprising with no more difference in the gears that they have.

If I were to drop either one to anything it would be a 3.23

If I could come up with a clean hsg I might even consider dropping the hemi car to a 2.94 and roll on with it,,,might.

 

[R413]

If I could come up with a clean hsg I might even consider dropping the hemi car to a 2.94 and roll on with it,,,might.

This would be a mistake for a Hemi, they are not a low RPM engine. Just kills the power, and uses more fuel. It has been tried.

does the same for a 392 hemi from the 50’s.

 

[Darter6]

I went from 4.10's in my Hemi car to 3.23. Much better for me. Still smokes the tires with ease.
Dr.Diff said he will have more sets of 3.23 for the Dana 60 in 3-4 months. I have a Dana 60 in my old truck with 4.10's.
Since I don't tow anymore I'll be doing that swap.

 

[33 IMP]

I went from 4.10's in my Hemi car to 3.23. Much better for me. Still smokes the tires with ease.
Dr.Diff said he will have more sets of 3.23 for the Dana 60 in 3-4 months. I have a Dana 60 in my old truck with 4.10's.
Since I don't tow anymore I'll be doing that swap.

I daily drove my A12 with a 4.10 dana on LA area freeways for years. I contemplated changing to 3.54, but I didn't think the change would be worth the effort. I WOULD change to the 3.23s from Dr Diff.

 

[1 Wild R/T]

I have 4:30 gears in this... Lil 340.... And a 518 O/D... O/D = 2.94....

 

[70bigblockdodge]

3.55s are good for nothing to low to burn 5-6 hours on the highway at 75-80 mph. To high for drag strip, while still being to low and forcing a 2-3 shift to make the stripe. They can work the same as 3.91s if you have a $1000 converter, which would be a better investment than 3.55 gear. I would stay with the 2.94 and upgrade engine parts.

 

[Darter6]

Doorkicker, to bad you are on the east coast.I'd buy your 2.94 741

 

[Archie Duiker]

I have a 66 charger with an 8-3/4 rear running 2.94 gears, open. A relatively decent 440 engine and your run-of-the-mill 727.

The gears are just a little too tall for me. I don't drive it on the highway but I must admit it cruise is pretty nice around 65 - 70. However, I have no interest in going that fast frankly. I just want to do burnouts and pin people's head back.

So I'm looking at dropping in a new set of gears with Cass's sure track. The question is do I run a 323 or a 355?

I had a 411 in an old firebird and that was way way too low. I was running 3,500 RPMs at 50 mph. So I'm not looking to do that again. But I'm sensing happiness is going to be one of those two gears.

With all that being said I still want to go get groceries and go hang out and ride around. But it also want to let the smoke out of my tires.

What say you?

If you want to be able to smoke the tires occasionally and still have an enjoyable ride, I would go with the 3:55s. However, the 3:23 is great for cruising and still provides some grunt on the street if you have a big block with a torque .cam. I owned a 68 hemi RR 4 speed for 46 years, running 3:54 & 4:10 on the street, but now have a 67 383/727 Satellite with Holley Sniper setup and 3:23 gears, and find it is much more enjoyable for cruising.

 

[68BabyBlue]

A year ago, I would switch off between my stock 440 GTX with 3:23s, and my Hemi with a 3:73. I used to drive the 440 car 100 miles to the Chrysler Nationals every year, and with 27 inch tires, could cruise with traffic on the four lane easily. Back in the day, the car was raced on a regular basis, and easily smoked the tires. I really enjoyed the 3:73 in the Hemi, which was only used around town. That ratio was well matched to the torque band of the stock engine.

My current GTX runs a milder (station wagon) cam in the stock 440, and with the 3:23 has lots of low end torque, with 27 inch rubber. This is my current preference, but I agree with others that the 3:55 is a pretty good compromise. I drove my former A33 car with a 3:54 and 28 inch tires from Iowa to PA when I bought it, and wouldn't want to repeat the experience.

 

[Butch Harley]

3.55 posi with 15" rims passion performance 4 speed with .73 fourth gear 70 MPH 2 grand RPM get

 

[Danny Tuel]

I have a 66 charger with an 8-3/4 rear running 2.94 gears, open. A relatively decent 440 engine and your run-of-the-mill 727.

The gears are just a little too tall for me. I don't drive it on the highway but I must admit it cruise is pretty nice around 65 - 70. However, I have no interest in going that fast frankly. I just want to do burnouts and pin people's head back.

So I'm looking at dropping in a new set of gears with Cass's sure track. The question is do I run a 323 or a 355?

I had a 411 in an old firebird and that was way way too low. I was running 3,500 RPMs at 50 mph. So I'm not looking to do that again. But I'm sensing happiness is going to be one of those two gears.

With all that being said I still want to go get groceries and go hang out and ride around. But it also want to let the smoke out of my tires.

What say you?

I'm running 3:55's in my 1966 Charger with warmed over 383. It will roast the tires but if that's all I really wanted I would probably go with 3:91's. Most Road Runners and Super Bee's came from the factory with 3:23's. It's a great highway gear. Remember Spinning Ain't Winning

 

[RM23U0A]

With the information you have given, I recommend 3.55. This will meet your needs. Wayne

 

[dusterkid]

I have 3.55 and 28" tires on my 69 Barracuda. 360 with 727. It's good for going to go get ice cream and driving around town, but if I were to do much highway driving I'm pretty sure I'd want 3.23.

 

[JC Boatguy]

Sleeper Satellite...3.55 SG, built 383, yes 55-60mph is really it, but it loves throwing you back in the seat!

 

[Larrry B.]

High compression 383 now with a TKX close ratio 5-speed, 3.23 auburn sure grip 8.75" with 28" tall rear tires. 2100 RPM at 80 mph.

I had 3.55's a couple of years ago with a rebuilt 727 and a 2800 stall converter before the 5-speed and it was ok but definitely gave a lot more noise all around.

I'm still faster than mosty everything leaving a stop light without trying to hard and can fly down the freeway far better than before.
When I bought the TKX the salesperson mentioned I might like the 3.55 better, I have no complaints...

 

[ldbjr138]

I have a 66 charger with an 8-3/4 rear running 2.94 gears, open. A relatively decent 440 engine and your run-of-the-mill 727.

The gears are just a little too tall for me. I don't drive it on the highway but I must admit it cruise is pretty nice around 65 - 70. However, I have no interest in going that fast frankly. I just want to do burnouts and pin people's head back.

So I'm looking at dropping in a new set of gears with Cass's sure track. The question is do I run a 323 or a 355?

I had a 411 in an old firebird and that was way way too low. I was running 3,500 RPMs at 50 mph. So I'm not looking to do that again. But I'm sensing happiness is going to be one of those two gears.

With all that being said I still want to go get groceries and go hang out and ride around. But it also want to let the smoke out of my tires.

What say you?

If you want to go max acceleration go with the 4:10 or bigger rear.

 

[YY1]

If you can't decide, you could hold out for a 50's 3.31 set (provided you have a 741 case).

They also made a 3.40 gearset for circle track at some point. I've seen one.