Daily driver gear ratio 8 3/4 rearend

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Hi everyone just like the title says. I currently looking for a opinion on the best gear ratio for daily street use (highway including sometimes) but to also have fun with I currently have a slightly modified 440 rb motor in with a Hughes whiplash cam, 727 torqueflite auto transmission, heavy duty driveline, wilwood disc brakes in the front with drums in the rear, calvert adjustable shocks in rear as well in the front, tire sizes are 225/60 in front with 265/50 in rear
 
Your tire sizes are a bit small at 25.6 inches in diameter.
But they will work with a 2.94 gear and feel like a 3.23.
I have 2.94's and work great with my 268H comp cam, light stall and 28 inch tall tires.
Swift take off yet good manners on the highway.
2.94 were common among 66-67 B bodies and also many Imperials.
Typically cheaper and easier to find than the higher demanding 3.23 and 3.55.
Regardless of which ratio you choose make sure you match up the speedo pinion gear for an accurate reading.
Hope this helps.
 
I like 3.23 with a 440 and 3.55 with a 383.

Just FYI with a 3.23 your RPM's will be about 2400 @ 55, 3000 @ 70, 3500 @ 80 and 4350 @ 100.
3.55 - 2600 @ 55, 3350 @ 70, 3800 @ 80, and 4800 @ 100

On anything I build I figure at some point I will want to take a road trip and I want to keep up with traffic. I don't like to run a 440 above 3000 for long periods so the 3.23 would be my preferred gear ratio......for a cruiser. Now the 3.55 will be way more fun to drive but unless you live in town and don't drive much highway I would think twice about it.

I had a buddy one time that had a 2.7 something gear ratio and wanted to go to 3.91's so I told him to drive his car around in 2nd gear for a week.....he ended up going with 3.55's

Just my $.02
 
As I like to feel some acceleration with little throttle input, I would more side with @cbarge and the 2.94 with your shorter tires. With the H78-14 tires the cars came with, the 2.76 ratio was good for about 28mph/1000rpm. With the 383 2bbl in our '66 Newport, it would move pretty good in traffic, but then I was not seeking to stay ahead of it, just blend in. But too, Chrysler seemed to spec out their TFs to upshift a bit early from 1st and 2nd, so that slowed things down a bit, from my experiences. I found a way to fix that, but that's another story. 3.23s in my '70 Monaco with H78-15 tires was good for about 25mph/1000rpm.

Fuel economy on trips is more important now than when the cars were new, so no need to really compromise that, to me. But by the same token, as long as it will lay some rubber from a stop, that's good enough for me, then and now, as wheelspin is wasted energy . . . plain and simple. NOT to forget about issues of wet pavement, too.

Key thing, to me, is to have the engine in the lower end of its torque band when on the highway. Especially in the 70mph range, which means there can be a good bit of power reserve for passing or other situations you might need to accelerate out of, without geting near the engine's red line. Which might also mean needing "passing gear past 75mph", where the 2.76s and 2.94s can work well.

When I was growing up in the later 1960s, "serious" performance cars usually had 3.91s or 4.10s "on the street", but these cars did not usually get out of town and freeway driving was not one of their main operational modes. When freeways were encountered, they usually drove 55mph due to the higher engine speeds. But then, too, gas was about 30 cents/gallon back then. It looked cool to drive around with all of the windows down and such, but not exactly what you might desire on a trip to the next town in summer (no a/c due to the "power drain" on the engine). So l liked our Newport with its 2.76s and the capability to run 75-90mph with no problems, no matter where, with full a/c blowing cold.

But the bad thing is that almost any modern turbo 4 with its gazillion-speed automatic will easily make our old big engines look weak. So "having somr fun" might require some discretion lest somebody might get embarassed. NOT to forget the 5.0L Mustangers who seem to always desire to prove their superiority on the street. BUT those guys can be really easy to bait, too! LOL Just pull up next to them at a red light and leave before they do. Don't even need full throttle, either! As soon as they realize what has just happened and THEY are not the ones in front, then you hear their rpms come up as they accelerate by you at past the posted speed limits. Such fun, even with my anemic '80 Newport 360 2bbl!

So, the 3.23s with the shorter tires might be your best option. Or the 2.94s @cbarge mentioned. Everything's a compromise and judgment call. Your money (spent or saved on gas). Your dreams/desires. Your judgment call.

Enjoy!
CBODY67
 
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Just an offer I have a good set of 3.23 sure grip in the Fury now and I want to switch to a 3.91 or 3.73 as I have an OD trans. I just rebuilt the rear with all new gears and it works great. I would be willing to trade.
 
Many a story back in the old day of someone going from 3.23:1 to 2.76:1 "for better gas mileage" because lower RPM's = better gas mileage.

But their highway gas mileage actually got worse.

Why?

Because lower gears = higher RPM for a given road speed = higher engine vacuum = better gas mileage. With the taller gears you're lugging on the highway and it takes greater throttle input to make something happen, liken when pulling hills = lower engine vacuum = worse gas mileage.

Lower gears = better torque @ smaller throttle openings = better gas mileage.

Your mileage may vary.
 
I found a way to fix that, but that's another story.

I was dissatisfied with the factory shifts points from my very first drive in a TF equipped Mopar, a $50 Blue Greenish Poly Pushbutton'64 Dodge wagon, Custom 440 or something like that. I always had to explain it to people, "no it has a 318 but look, its as big as a 440" ;]

I just a) took the slop out of the kickdown linkage, and b) threaded it back until I liked the shift points under throttle, usually a long ways back, sometimes all the way to the end of the thread to make up for worn pivot points along the line.

The only downside to this is when taking Grandma to the store, low rpm/throttle application shifts can be a little jolting.

I just don't like shifts I can't feel.


I need to feel them and know what gear I'm in, and know my engine speed.

I've always needed to be super connected to the car like that, audio input, as well as visual.

I mostly always have the stereo off so I can think, but mostly listen to the car.

Wife and I drove all the way from WA to CA and best with no stereo in the car, trunk speaker wires in her car had been ripped out from loading firewood probably.

I'm super blessed/cursed to live at the bottom of a windy 2.5 drive up and out of a canyon, this is dirt and gravel. It's a road course. If we closed it down, we could do time trials on it, but as it is, you have to negotiate things like UPS drivers, even semis, as you're hauling @ss outa there - a well prepped Subaru helps - so it's real world driving, and a great place to manually shift your auto trans, as you need to be in a lower gear for better throttle response.

Coming down the canyon is always a downshift into 2nd gear to hold the car back, and just let it wail. On deccel, you'll find out if your valve guides/seal are any good, as you fly down the hill at near 4k RPM = roughly 40mph, with foot clear off the gas, correspondingly very high vacuum.

My first Subaru had an auto trans that refused to hold high RPM on downhills and most newer cars refuse to even engage a lower gear going down a hill, the gear will finally engage when you reach whatever piddly speed the car has decided is safe.

My current Subaru since 2017 is a 5sp, and I toggle back and forth between 2nd and third as needed on the way out or back in.

With a properly setup auto trans, you should have very crisp kickdown/shift, giving you a lower when needed, rather than having to do it manually, because then you find yourself running down the highway in 3, for a while, til you notice the tach needle is too high...

I recommend people leave it in D driving out and let the car sort it out, but in some cases, you have to select 2 yourself to negotiate things like hairpin turns on 15% slope and washboards, rocks the size of graprefruit or melons, moose, bear, and even worse people who hunt them and their stupidly loud pickup trucks.
 
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If you don't mind opening up the transmission, you could go 3.23 sure grip and install a low gearset in the trans, like i did. With a 2.77:1 1st gear, it's like having a 3.6:1 rear ratio on take off. Still have good cruisability with 3.23s.
Simple matter of changing out the front planetary and sun gear.
I haven't driven it yet, but this is what I've done to my '71 Fury 440 car.
Good luck
 
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On the later 904-family automatics (think 1980 and so), the Slant 6 automatics had that low low gear ratio too. It is a 4-pinion design just like the HEMI 727s, from what my automatic trans operative said, so we did it. In the '80 Newport 360 2bbl and 2.41 rear axle, it kind of put things back to normal, 2.45x2.76, basically. Made things feel more "right" with that ratio combination, but nothing spectacular per se. But good to know it was there.

Enjoy!
CBODY67
 
Hi everyone just like the title says. I currently looking for a opinion on the best gear ratio for daily street use (highway including sometimes) but to also have fun with I currently have a slightly modified 440 rb motor in with a Hughes whiplash cam, 727 torqueflite auto transmission, heavy duty driveline, wilwood disc brakes in the front with drums in the rear, calvert adjustable shocks in rear as well in the front, tire sizes are 225/60 in front with 265/50 in rear
3.23 gear
 
I run 2.76 in all my old cars with automatics, but without overdrives. The reduced noise and much better cruisability more than make up for the slightly reduced performance off the line. Honestly as long as your aren't drag racing, I really don't notice a difference off the line, but at 70mph, there's a huge difference. In terms of lugging, as was mentioned, I have found that with a good running small block engine, you can get away with around 2.3:1 final drive ratio (with an overdrive trans) before any significant lugging problems occur. So the 2.76 ratio is no where near a problem. When I swapped from 3.23 to 2.76 in my Barracuda, I went from 15mpg to 19mpg on the freeway.

I find that 3.23 is a great ratio with an overdrive transmission as long as you aren't towing too much. If so, then go to 3.55.

With a manual trans, that's when you really need an overdrive. Even 2.94 is pushing it starting off the line and 2.76 is really hard on the clutch. But you can get away with higher gears if you have more low end torque.
 
I run 2.76 in all my old cars with automatics, but without overdrives. The reduced noise and much better cruisability more than make up for the slightly reduced performance off the line. Honestly as long as your aren't drag racing, I really don't notice a difference off the line, but at 70mph, there's a huge difference. In terms of lugging, as was mentioned, I have found that with a good running small block engine, you can get away with around 2.3:1 final drive ratio (with an overdrive trans) before any significant lugging problems occur. So the 2.76 ratio is no where near a problem. When I swapped from 3.23 to 2.76 in my Barracuda, I went from 15mpg to 19mpg on the freeway.

I find that 3.23 is a great ratio with an overdrive transmission as long as you aren't towing too much. If so, then go to 3.55.

With a manual trans, that's when you really need an overdrive. Even 2.94 is pushing it starting off the line and 2.76 is really hard on the clutch. But you can get away with higher gears if you have more low end torque.
THE 3.23 is the tow ratio used in the A-35 tow package in the early yrs(up to 71) a c body will tow 9000#! the problem with the over drive trans is u have to modify the trans tunnel as the tail end is bigger . if u want mpg buy a cummins with a 5 speed stick .
 
3.23 gear
thats my pick its gives good out of the hole & willmonly kill the mpgs by 2points on the highway now if u dont mind a bit slower off the line then 2.76 is ok my NYB had 3.23 gears it it per te build sheet but tey was removed & replaced long before i got her now unless im trying to match a new hell cat off the line it dose ok i just wish the mpg's was higher but she is a heavy car
 
3.23's were hugely popular back in the day, almost as the one universal ratio that does it all quite well.

2.76's were the highway gears of choice and 3.91's were the closest thing to a "4.11 posi" that all the Chevy guys raved about.

3.55's were unusual.

The DANA Corp "Track Pack" Trak Lok ratios were 3.54 and and 4.10.
 
3.23's were hugely popular back in the day, almost as the one universal ratio that does it all quite well.

2.76's were the highway gears of choice and 3.91's were the closest thing to a "4.11 posi" that all the Chevy guys raved about.

3.55's were unusual.

The DANA Corp "Track Pack" Trak Lok ratios were 3.54 and and 4.10.
but gas was cheap then too
 
I remember gas @ $.25 a gallon when I first started paying attention, cigs were about the same price in VA.

$.25 in 1973 = $1.66 now, so even adjusted for inflation gas was way cheap.
 
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