What's you favorite gear ratio for the street?

[451Mopar]

With a 26"-27" tall tire, and a street type engine with lower stall converter, I like the 3.55:1 8-3/4" or 3.54:1 Dana 60. Ratio also works good with overdrive transmissions.
That is just a bit more than the usual factory 3.23:1 gear. Still a decent gear if you do highway driving.
With taller 28" to 30" tires, or a engine built for higher RPM with a higher stall converter, then 3.91:1 or 4.10:1.
I never had a 3.73:1, but it sounds like a decent ratio too.
The lower gear you have (higher number) the higher the driveshaft speed will be (and engine RPM if not an overdrive).
With the higher driveshaft speeds, I like a upgraded (diameter and/or material) and well balanced driveshaft.

 

[skicker]

The 65 Coronet has 4.11's with a 440 and a 4 speed with 29" tires...60 mph is about it with open headers...

The 69 Dart has 3.91's with a 340 and a 727 but the 4200 convertor makes it seem like more maybe 55 or so is about it...

The 72 Duster has a 3.55's with a 416 and a 727 and the 3500 convertor makes it pretty decent to around 65 mph...

The 70 Satellite has 3.23's with a 727 and 30"" tall rear tires with a stock convertor...definitely the only car I have for running freeway speeds...

I've come to the conclusion that you just need a car for every occasion...at that point gear ratio will always be correct...

 

[gooser]

i've had everything from stock 3.23 to 4.86 in my roadrunner but now i have a 4.30 gear in it for the last 28 years

 

[70ChargerRT]

I had 3.73:1 in a 8.750",
didn't notice any loss of power or difference in the 1/4 mile performance either
from a 3.91:1 gear, barely a difference from a 4.10:1 too...
(like 2,800 rpm w/3.73:1 - 2,900 rpm w/3.91:1 29" tire, freeway at 65)

I preferred to run 'steep gears' in my cars, taller tires/wider too usually,
bigger contact patch...

Back in the day when gas was $99 or less, I ran 5.13:1 in my 68 Charger R/T
nobody beat me 'out of the hole' & as long as you didn't go too far on the freeway
it wasn't as bad as some would think 3,700-3,800rpm at a constant 65,
29.5x10.5w's on the rear, cut them down a bit, with a J converter & 4200 stall,
it was a great gear...
I went back roads mostly, wasn't concerned about milage, I wanted the best performance...

People are 'pussified' today, or just getting old, acting like it too
or whine, want to influence others in what they have & what they want (you) to do (followers),
for you to accept them & their style of builds...
I never did get that ****, I build my cars for me, not by committee
or to appease some other crowd...

Now, I'm not into driving a bunch of freeway miles, in an old muscle car anyway...
Got other cars/trucks for that ****...

I ran anything from 3.23:1, 3.55:1, 3.73:1, 3.90/3.91:1, when mostly street driven/cruising
or 4.10:1, 4.30:1, 4.56:1, 4.88:1, 5.13.1 if I knew I was gonna' race like Friday or Saturday nights
I had the gambit of gears, you name it I had it, with a sure-grip or spool
I got from an old racer clearing out his shed, Bill Stammerjohn, (spell)
a Sacramento guy who was well known for MoPar engine builder, cylinder heads & porting

There's nothing like gear ratio to get a heavy car moving quickly
I always ran big tall rear tires too, 1st was N50/15 were
like 27.5" to 28" depending on what brand or what width or rim etc.
a lot taller than the 14's x 24"- 26" you could get at the time, these cars came with...
Than later when better wide tires, better compounds came out,
I ran the tallest/widest tires I could fit some 30"s mostly 29" or 29.5",
on my many RRs or Chargers'... It helped cut the gear ratio a bit
& for more MPH, less trap RPM" it was always about the 1/4 mile",
not posing by my car at a show or a cruise...

Now I'd go with a lower 1st gear ratio to get that 10:1+ combined gear needed in 1st
& run a milder gear for speed, like a 3.55:1, 3.73:1 or 3.91:1
or an over/under drive like a gear-venders,
But they are expensive, so is a manual OD conversion, 5-6 speed
when I was younger; there's no way I'd have afforded that ever
barely want to even spend that now
IMHFO takes the fun out of it too, these old muscle cars
are supposed to be a lil' obnoxious
unless you are driving nothing but freeway mile,
then why do it ?
You only live once, enjoy it...

MY Pro-gas 49 Ford I ran 4.88:1 w/33"x 18" tires, drove it all over the place
even down the freeway, did many a cruise night in it, many 100+ miles away even...
Concord to either San Jose, Cupertino, Fremont, Fairfield, Modesto or to Sacramento, even Reno
I drove it to Pheonix, from Concord Ca. for
(did it & won it in my 67 Camaro S/C a couple years earlier too)
Super Chevy Sunday "Worlds Fasted Street' Car" race, in 1989-ish 1st
3,100#s 477cid BBC 4.5" bore 3.75" stroke, .880" gvl roller on alcohol injected
(Methanol at the track only) Tunnel-ram with Enderle hat, 80a pump
had gasoline nozzles in it, for the trip down,
so I could get fuel along the way at the pump
then changed to Alky nozzles, at the track
(later & then 1995-ish a 526cid Milodon Hemi, Blown Inj Hemi, didn't drive it down then,
just the 20 mile loop we had to do & restart after it, it was towed, still had the 4.88:1 gear
a lot more heavy hitters showed up in 1995 era, I took 3rd, but I broke a rocker in the semi's
running 7.90's at 180-ish, next guy up/fastest loser, took my place in the finals)
Mikes Transmission Powerglide 4,500 stall/flash to 5,000,
tight converter in high gear for N2O,
but wasn't running any N2O, 16 Gal. cell was a PITA way too many stops
89-ish I won the class too, 8.98 @ 160-ish black-tracking the whole damn way
(it'd run high 7.90s at like 178-ish on 33" x 15" slicks)
I wasn't as bad as some may think, 3,300 rpm on the hi-way going like 65 mph
it got like 13-14 mph if I was being cool, I was surprised...
didn't need no OD ****
View attachment 1743484

Right now my car 68 RR street beast, has a 3.23:1 gear & sure-grip
near 28" rear tire P295/50/15 on a lil' narrower wheel
good for up here driving country roads, not to steep or too high

I do need an overdrive, if I want to drive long distances, not really in my plans
maybe a Gear-venders OD
I'd like to go to a 5-6 speed manual, but not spend $10k
on a trans, clutch, peddle, MC, driveshaft & gears, after all's said & done
or to have to hack the tunnel...

View attachment 1743504

You don’t need an OD, especially a 6-speed. It takes the fun out of it and you’ll have to hack the tunnel Man I’d love to make you eat those words! Would love to take you for a ride or better yet, let you drive my car.

 

[Hey-O]

5.7 Hemi, 545RFE Transmission, 323 gears. I'm not worried about being the quickest around town, it's the highway I'm concerned about. I spent years driving around with tractor gears, no thanks.

 

[dfrazz]

I did a comparison of 3.91's to 3.23's in my '69 RR -

 

[TorRed]

Ran 3.91 or 4.10 back in the day with a 28" tire on a 383 RR with 727 trans. Highway driving was limited to about 60 MPH which wasn't a big deal since the Feds lowered the "national speed limit" to 55 right as I was getting my license. Now that 70 MPH is the norm again with traffic generally running 5-10 MPH above that, I need less gear for any highway driving which is why I have 4.10 gears and a Gear Vendors unit to put in. The GV is only .78 overdrive so basically makes my 4.10s into 3.20s or roughly the preferred highway gear for these cars. That said, I'm not going to be doing a lot of highway driving. One thing no ones really talked about so far is that stock stroke 383s need more gear than 440s so a little extra gear is a good/necessary thing.

 

[Coelacanth]

After reading all the responses, I'm leaning towards 3.73's with my 383 Magnum/28" tires...

 

[33 IMP]

Overdrive is icing on the cake. It's what every 833 or Torqueflite equipped car is lacking. You should be able to do burnouts with a 4.10 and cruse at 65 or so at 2000 rpm or less. The best of both worlds.

Agree, wholeheartedly.
Problem is, unlike 99% of the engines out there being currently hot-rodded, there is no easy fit overdrive available for a bbm. (But I'm SURE you know that!). Gv, small block mopar with an adapter, or GM with an adapter. Nothing cheap or easy..
I've still got 4.10s in my rr, cause it's an A12 and that's what's supposed to be in it. It really needs Dr.Diff's 3.23s.
On the other hand, 3.50s are coming out of my Opel, and 4.10s/spool/alum center going in. That car won't be driving any long trips. And I have some 33" tall tires that fit. I could put an OD in it easily enough, but I think a transbrake 400 is more likely, to replace the 400 that's in it.

 

[33 IMP]

After reading all the responses, I'm leaning towards 3.73's with my 383 Magnum/28" tires...

What does it have now? How much highway flying do you do? (You can calculate expected rpm, at a given speed.)

 

[Coelacanth]

3.23 SureGrip and mild 383, previously running 255-60-15's on the back but I have some new wheels and 275-60-15's going on there next spring. Most of my driving will be around town, my Charger won't be used much for road trips, but I do want it to be somewhat driveable on those infrequent highway drives. So, my needle is leaning more towards acceleration than top speed.

My rationale is, going from 3.23's and smaller tire to a larger tire and only 3.55's might not be enough of a noticeable difference; 3.73's might pack a little bigger punch with the move up in tire diameter.

 

[33 IMP]

3.23 SureGrip and mild 383, previously running 255-60-15's on the back but I have some new wheels and 275-60-15's going on there next spring. Most of my driving will be around town, my Charger won't be used much for road trips, but I do want it to be somewhat driveable on those infrequent highway drives. So, my needle is leaning more towards acceleration than top speed.

My rationale is, going from 3.23's and smaller tire to a larger tire and only 3.55's might not be enough of a noticeable difference; 3.73's might pack a little bigger punch with the move up in tire diameter.

Agree. Considering intended use, I'd consider 3.73s too (I won't do a gear change for less than a half ratio). If it turns out to be too short, taller than 28" tires are available. (265/75x15).

 

[440 4 speed]

I answered 4.10’s in a previous post, I would like to add that this is with 295/65R15 Drag Radials which are 29.5” tall. Mathematically it is within 75 rpm of 3.55 gears with the factory F70-14 (26.2” diameter) tire.

In my ‘58 Apache I run a 3.55 gear in an 8 3/4 Mopar rear with 235/70R15 which are 27.95” diameter. It’s a little over 3000 rpm at 70 mph. But in all honesty, an overdrive transmission would be more ideal. The Chevy has a 454 with a RV cam that makes great torque from off idle to 4500 rpm and a stock converter, with OD it would be around 2100 rpm at 70.

The GTX has a 440 with a .509/292 cam and an efficient 9 1/2” converter. The cam starts coming strong around 3300 rpm which coincides with what the converter flashes to. It does just fine on the occasional trip running 70 mph down the interstate because it’s up on the cam, and under part throttle the converter is pretty tight.

View attachment 17435670

My point in all of this is that you need to consider the entire combination and it’s intended use. Personally I’d run a 3.55 gear with a stock or mildly built big block B Body and something like 275/60-15 rear tires. It would be a well mannered street machine that could roast the tires at will. More cam or converter would need more gear. It depends on how far down the page you go…

We have 275/60x15 and 3:54 gears. I think 3000 rpm gave me 65MPH. Don’t really like running at 3500 rpm. It’s been 4 years since we started this refurbish. Just have to get the car completed.

 

[Cranky]

Don't 'stink' I replied to this thread but....put a 4.88 in my 340 Cuda for awhile and man, talk about fun! Left the shifter in 2nd on the launch because....well, you know. 3rd gear was quick and so was 70 mph! The 275/60's had a hard time getting traction so had to use descretion with the go pedal. The only reason the 88's were in it was to make sure they were quiet before selling them. Got to admit, they were fun in town!

 

[70ChargerRT]

Agree, wholeheartedly.
Problem is, unlike 99% of the engines out there being currently hot-rodded, there is no easy fit overdrive available for a bbm. (But I'm SURE you know that!). Gv, small block mopar with an adapter, or GM with an adapter. Nothing cheap or easy..
I've still got 4.10s in my rr, cause it's an A12 and that's what's supposed to be in it. It really needs Dr.Diff's 3.23s.
On the other hand, 3.50s are coming out of my Opel, and 4.10s/spool/alum center going in. That car won't be driving any long trips. And I have some 33" tall tires that fit. I could put an OD in it easily enough, but I think a transbrake 400 is more likely, to replace the 400 that's in it.

So is the Gear Vendor a hard install?

 

[33 IMP]

So is the Gear Vendor a hard install?

I don't think so. It's kinda designed to be a fairly easy install, don't have to do much to the trans tunnel, if anything. And it's STRONG, (Basically a single lenco style unit). And can be added to almost any trans, stick or auto.
Problem is, it's expensive, and not a real big overdrive ratio.
My comment "no easy install" was more referring to the easy o.d.s available for small block mopars and Fords and chevys, direct bolt-ups for them.

 

[PROSTOCKTOM]

Since the OP asked about 8-3/4 specifically.

Unless you have an overdrive a 3.23 is a nice all around ratio that is driveable and works in most situations.


Now, off topic I like using Dana 61's because you get the Dana look and can have 3.07 & 3.31 ratios.

I've had two pickups with the 3.07's and really like those for driving around on the interstate. I also have a cut down 61 housing and a set of 3.31's for a project someday.

Tom

 

[33 IMP]

Since the OP asked about 8-3/4 specifically.

Unless you have an overdrive a 3.23 is a nice all around ratio that is driveable and works in most situations.


Now, off topic I like using Dana 61's because you get the Dana look and can have 3.07 & 3.31 ratios.

I've had two pickups with the 3.07's and really like those for driving around on the interstate. I also have a cut down 61 housing and a set of 3.31's for a project someday.

Tom

I have always been surprised by the lack of love for a 61. The strength of a Dana, gear ratios for freeway flying. Build a powerful hi-torque engine (turboed?), gear it for top end. Won't need an overdrive. I'm guessing they are all too wide for a car application.
(Dr Diff made 3.23 for a 60, wish I had some for my 60, but a 61 could do the same thing with 3.07/3.31.)