3:55 or 3:23?

[69 GTX]

By highway do you mean 75 mph or 60? If it doesn't see the interstate much 3:54. If most your time is on the interstate 3:23. If it were a 440 I'd say 3:23, because of more hp/tq. 383 I'd go 3:54

 

[6PKRTSE]

By highway do you mean 75 mph or 60? If it doesn't see the interstate much 3:54. If most your time is on the interstate 3:23. If it were a 440 I'd say 3:23, because of more hp/tq. 383 I'd go 3:54

I have 4:10's in my red Charger & I drive it everywhere for the last 27 years. The older I get I have been thinking about switching it down to 3:55's. I probably will for sure once the more race than street Challenger is done. I will tame down the Charger a bit.

 

[HT413]

I have 4:10's in my red Charger & I drive it everywhere for the last 27 years. The older I get I have been thinking about switching it down to 3:55's. I probably will for sure once the more race than street Challenger is done. I will tame down the Charger a bit.

4.10's are an awesome gearset, though obviously not what the OP is looking for. Killer acceleration and highway cruising is just within reach... or maybe just out of reach My 30" tires are the only thing that makes it possible, but I suppose they really knock that 4.10 down toward 3.91's. 3000 rpm at like 65mph.

 

[Cornpatch MO]

See what happens when you ask that kind of question? Definate opposing opinions. Mine is: with 28" tall tires and 4 speed, 440 engine , 3:55 sure grip. Lots of fun to drive around town. More RPM than I would like at 60-65 MPH on road cruising. Drag strip doesn't take long till time to bang another gear. I have a 3:23 diff. sure grip that I am thinking of checking out and swapping. IMO an excellent all around rear gear The 440 has enough torque to work well with a 3;23. I really don't expect a lot of difference on the drag strip, and this is not a race car. It may be even better E.T. with the 3:23.
And you have 27" tires which would convince me to go with the 3:23...........................MO

 

[Steve009]

I'd go 3.55. I just took my 3.23 out of my 64 (383, 4speed). with my 29" tall tire it was a dog. when I had the smaller tires (27" I think) the 3.23 wasn't bad but I think the 3.55 is the perfect balance between highway and givenr' light to light. I just put in 4.10s today and cant wait to test them out so maybe my opinion on highway gears in jaded lol

 

[Fran Blacker]

Ran 3.54's liked them and had 26" tire. Drove from Ct to Buffalo no problem. Had a 64 Olds Starfire with 3.54's .

 

[Nacho-RT74]

Very good diff opinions, but need to consider

Converter stall
Tires size

Those calculators are just an aproximation because the converter eficiency changes A LOT their given values.

Aside that, they give a value allways pushing the car, without consider the inertia. You can go at lower RPMs than the calculators depending of the road

We can make maths... 3.55 is around just 10% difference from 3.23... so will be around the same difference with speed, RPMs and mileage. Both actually will work great and both were offered as factory setups on performance setups.

I changed from 3.23 to 3.55 and I barelly could notice a big diff. Maybe a crispy response.

My opinion is for more street use, the higher ratio, for more highway use maybe lower.

You will be able to decide just testing personally.

 

[Nacho-RT74]

I can't recall the tach readings on my old 400/727 setup with MP 160K TC and on those days I barelly saw interstate roads, but when I built my 451 stroker with MP 175K TC ( both on 3.55 SG and 255/60-15 tires ) I was dating a girl 100 miles from home, so I traveled a lot and ASSUMING the speedo was correct, I was able to see around 100 miles at around 3200 RPMs ( flat areas of the highway ). Couldn't make more due pinging and vibrations somewhere at drive line.

 

[EddieE]

I have a 3.23 in a cuda (sorry wrong forum) with a stroked 340 (416) with 465 HP and 530 torque. I got a few 833's from Jamie Passon because I couldn't make my mind up. The 4 speed overdrive drove me nuts, it was like driving a 3 speed because my engine doesn't really smooth out until 2000+ rpm's. So I had to be going REALLY fast to use it. I gave it back to Jamie and he made me another 833 trans with what I think is a 3.09 first gear. Maybe from a Feather Duster or something like that. IMHO this is the perfect combination. Car runs on 15" 235 Radial T/A's so there's no way to come out of the hole without wheelspin, but the car is a blast through all of the gears. Jamie (or someone) can tell you what the downside of the wider ratio is on a dragstrip, but on the street you will fall in love with it. Plus the highway cruise is a lot more bearable than 3.55, 4.10, etc. IMHO if you just want to get out of the hole and you have a similar (or stronger) engine setup, it's great.

 

[Sonny Black]

Sonny says.........355

 

[Hippy]

A old rule of thumb is for every 1" of tire that you go up/down in size your ratio will change .2

Ex: 28 " tire 3:23 gear
27" tire 3:43 gear
26" tire 3:63 Gear

These are approximate BUT very close
Back in the late 60's when the 60 Series tires was the craze a F 60 with a 3:91 gear vs a L 60 with 4:30 gear would pull the same RPM at 60 MPH

Jim

 

[joemish]

Which rear end would you guys prefer in a Super Bee that sees quite a bit of Hiway driving? Tires are 27 tall, mild cam , 383. 727 TF transmission.

A 323 rear would be a good highway gear