Your favorite rear end/final drive ratio and why?

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I think it comes down to intended use of your car and another factor is your tire height. Like I posted earlier I run 3.23’s but I also have a fairly short tire that’s 25.4” tall.
 
The car in my avatar was the most fun with 3.55 gears.It was a heavy BB car. Tried 3.73 gears but preferred the 3.55's.
I ran a couple of big block chargers with 4.10's for years but I just don't like the higher cruise rpm anymore.

I bought my old 68 Chrysler 300 back and it has 3.23 gears.Going to leave it alone other than adding a suregrip.

I just bought a 72 Duster with a 440 and it feels like a 3.23. I will probably leave it in there until I am done with the heads/cam swap and see if it wants more. 3.55 is as low as I will go. Mine are much more street than strip these days.
 
MRGTX said:
It seems like the consensus is going the other way. You would stick with the acceleration oriented gears?
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Depends what you value the most, you could try to find more traction with suspension and tires.
What gearing needed for performance wise is to get it into the powerband at most mph, you want to be able to spend as much time in the top 10% of the power curve looks like about 4200 rpm and up (4000-6000rpm) in a full throttle run, of course it's also a street car so compromises could be made.
But after spending all that money I wouldn't want to get it so it's hard to spend much time over 4000 rpm when I want kind of makes the engine a little pointless.
 
As said in an earlier post, rear gearing is application dependent. My current '69 Dart build is going to be a weekend car, not a daily driver. It's based on a 380-horse 360 crate motor that I plan to modify a bit to get over 400hp out of it.
Since it's going to be more 'toy' than anything I'm going with a 4.30 rear gear behind a 200-4R OD trans. I had the trans built as a manual-shift, reverse-pattern with a 2800-rpm lockup converter. Theoretically this combo will give me the best of both worlds. The 4.30 gears will be fun around town and the 0.67 OD will make them behave like 2.88 gears on the freeway. Others here on FABO with a similar lockup 200-4R have stated it almost feels like a 5th gear when lockup hits.
Other deciding factors for the 200-4R were that it fits in an A-body tunnel without major tunnel surgery and there is no computer involved with the transmission. Since mine was built as a manual-shift, I don't need to worry about a throttle valve cable or adjustment.
 
ocdart said:
As said in an earlier post, rear gearing is application dependent. My current '69 Dart build is going to be a weekend car, not a daily driver. It's based on a 380-horse 360 crate motor that I plan to modify a bit to get over 400hp out of it.
Since it's going to be more 'toy' than anything I'm going with a 4.30 rear gear behind a 200-4R OD trans. I had the trans built as a manual-shift, reverse-pattern with a 2800-rpm lockup converter. Theoretically this combo will give me the best of both worlds. The 4.30 gears will be fun around town and the 0.67 OD will make them behave like 2.88 gears on the freeway. Others here on FABO with a similar lockup 200-4R have stated it almost feels like a 5th gear when lockup hits.
Other deciding factors for the 200-4R were that it fits in an A-body tunnel without major tunnel surgery and there is no computer involved with the transmission. Since mine was built as a manual-shift, I don't need to worry about a throttle valve cable or adjustment.
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If it's the Magnum 380 crate you already make over 400 hp the 3 I seen dyno made 400-410 hp.

I got one with 2800 stall but 2.76 gears, to get into the powerband I got drop it into 1st and get up to 40-50 mph before hammering it, way too much mph intown to really get to play with.
 
Just think how many gallons of gas you wasted and how many people passed you thinking, why is that muscle car going so slow.
Hemirunner said:
I commuted 4.5 hours one way On the interstate to college for years with a 4.10 gear and 26” tires. Luckily it was with full exhaust lol. I run a 3.73 with a GV OD and 28” these days.
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Dodge dart sport 360 here. I had 3.55's before and they ran well. Also cam was the 280 mopar cam. Now run 3.91's and a 292 mopar cam seems to run happier! So my vote is 3.91's!
 
It all depends on the use of the car. Years ago, i had a coworker with a 71 Cuda,440 4 speed and 4.30 gears, he was always blowing MY Cuda this, MY Cuda that! I asked him how long he would take his car out at night, his reply-usually run thru a tank of gas, some of that racing fuel. One time he started blowing, I had just got back from a 1800 mile roadtrip one extended weekend with my 69 Coronet R/T, 440 auto, 3.23 gears. I asked him who he thought had the most fun, him driving around town for a couple hours with his 4.30 gears or I-that had just logged 1800 miles on the highway with my 3.23 gears. He didn't answer me and he never said another word about his Cuda, in fact he sold it a short tome later.
 
i run 3.23's with a 26" tall tire. on the highway it'll run out of speedo before engine and around town if i want to flex a little i can just drop it in 1st and hammer it.

it'll do a burn out and i can drive comfortably on the freeway that's really all i need.
 
More gears, more options. You don't have to sacrifice highway driving.
Good luck!
MRGTX said:
What did you pick? Why? Are you happy? Do you wish that you picked something different?


About four years back, after saving up a wad of cash, I had the chance to pick out my "dream" rear axle assembly. My vision for my car was to make it as fun as possible on curvy back roads, probably take it to the autocross at some point, and to generally make it exciting and engaging to drive. To me, this usually means higher revs and lots of shifting.

With that in mind, I chose a mechanical limited slip (Eaton Truetrac) with 4.10 gear ratio. After living with it with two different engines and two different transmissions (just did a 4spd swap), I am not sure if I would have been better off with a lower numerical (more highway oriented) ratio. The main problem seems to be the lack of an overdrive gear and engines that don't exactly love to rev. The two 5.9s I have had tend make their power down low where they don't need as much help from the short gears.

My current engine is a Blueprint 408 stroker making about 460 at the crank driving an A833 4spd with stock ratios. There's more than enough power to overwhelm the tires in almost any gear...at least with my 255 no-season BFG T/As.

Would it be more fun with 3.23s or 3.55s? I just don't know and experimenting is outside of my budget currently... I'm hoping to learn from you guys before I invest.
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MRGTX said:
What did you pick? Why? Are you happy? Do you wish that you picked something different?


About four years back, after saving up a wad of cash, I had the chance to pick out my "dream" rear axle assembly. My vision for my car was to make it as fun as possible on curvy back roads, probably take it to the autocross at some point, and to generally make it exciting and engaging to drive. To me, this usually means higher revs and lots of shifting.

With that in mind, I chose a mechanical limited slip (Eaton Truetrac) with 4.10 gear ratio. After living with it with two different engines and two different transmissions (just did a 4spd swap), I am not sure if I would have been better off with a lower numerical (more highway oriented) ratio. The main problem seems to be the lack of an overdrive gear and engines that don't exactly love to rev. The two 5.9s I have had tend make their power down low where they don't need as much help from the short gears.

My current engine is a Blueprint 408 stroker making about 460 at the crank driving an A833 4spd with stock ratios. There's more than enough power to overwhelm the tires in almost any gear...at least with my 255 no-season BFG T/As.

Would it be more fun with 3.23s or 3.55s? I just don't know and experimenting is outside of my budget currently... I'm hoping to learn from you guys before I invest.
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Well all I can say is I enjoy driving my cars (small block 4sp.) I am running 355.1
 
Your answer will vary from person to person.

When I was young and 10 minutes from the Strip, 4:56's behind a 727. With a 833 it was 4:88's. Could have cared less about anything over 55mph. My world was contained to a 20 mile radius....

With the Buick Grand national, it had a 3:42 with a 275 and OD so you could drive it anywhere...
And with a 540 in a Chevelle, Final drive was 1:1 and a 3:42 was more than a plenty with the Nash 5 speed.

My current car has 3:91's with a 14" tire. But I have a 3:23 and 3:55 hogs heads if I decide to tame the final drive. I don't intend on long distance trips when I put it back together this summer so the 3:91 is probably permanent....

JW
 
#1
Rat Bastid said:
For a street car? With an automatic 4.10’s. With a stick 4.56’s.

Ignore the tach. These engines were never designed to lumber along at 2200 RPM like a late model engine.
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#2
1971 CY Dodge Dart said:
Yea no thanks. Way to much gear for the street.
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#1: Good.

#2: Must'a got lost...somewhere down the line

My Duster came with 3.23s. Driving in San Francisco with 'em? Ha! It was a joke. ...my clutch din't think it was at all a funny joke neither.
 
MRGTX said:
What did you pick? Why? Are you happy? Do you wish that you picked something different?


About four years back, after saving up a wad of cash, I had the chance to pick out my "dream" rear axle assembly. My vision for my car was to make it as fun as possible on curvy back roads, probably take it to the autocross at some point, and to generally make it exciting and engaging to drive. To me, this usually means higher revs and lots of shifting.

With that in mind, I chose a mechanical limited slip (Eaton Truetrac) with 4.10 gear ratio. After living with it with two different engines and two different transmissions (just did a 4spd swap), I am not sure if I would have been better off with a lower numerical (more highway oriented) ratio. The main problem seems to be the lack of an overdrive gear and engines that don't exactly love to rev. The two 5.9s I have had tend make their power down low where they don't need as much help from the short gears.

My current engine is a Blueprint 408 stroker making about 460 at the crank driving an A833 4spd with stock ratios. There's more than enough power to overwhelm the tires in almost any gear...at least with my 255 no-season BFG T/As.

Would it be more fun with 3.23s or 3.55s? I just don't know and experimenting is outside of my budget currently... I'm hoping to learn from you guys before I invest.
Click to expand...
I'm in the process of building a 1967 Barracuda convertible. It will have a 360 magnum @ around 350-375 hp, 46RH transmission and 8 3/4 diff with 3.23 gears. Most of my driving in FL will be highway at 70 to 75 mph, so I'm looking to keep the rpm down in a reasonable range.
 
3.23's and 4-speed. never used 4th around town but it was like OD on the hiway with 27" rear tires. Slicks were same dia. so only used first 3 gears. Next time will use 25-26" slicks and keep tall tires for daily driving.
 
My combos:
1970 dart: 340, 727, 8 3/4 with 4.10 gears, 26" tall tire
1967 Fastback Barracuda: 440, 727, Dana 60 with 3.73 gears, 28" tall tire

Love them both for what they are, and wouldn't change a thing.
 
MRGTX said:
What did you pick? Why? Are you happy? Do you wish that you picked something different?


About four years back, after saving up a wad of cash, I had the chance to pick out my "dream" rear axle assembly. My vision for my car was to make it as fun as possible on curvy back roads, probably take it to the autocross at some point, and to generally make it exciting and engaging to drive. To me, this usually means higher revs and lots of shifting.

With that in mind, I chose a mechanical limited slip (Eaton Truetrac) with 4.10 gear ratio. After living with it with two different engines and two different transmissions (just did a 4spd swap), I am not sure if I would have been better off with a lower numerical (more highway oriented) ratio. The main problem seems to be the lack of an overdrive gear and engines that don't exactly love to rev. The two 5.9s I have had tend make their power down low where they don't need as much help from the short gears.

My current engine is a Blueprint 408 stroker making about 460 at the crank driving an A833 4spd with stock ratios. There's more than enough power to overwhelm the tires in almost any gear...at least with my 255 no-season BFG T/As.

Would it be more fun with 3.23s or 3.55s? I just don't know and experimenting is outside of my budget currently... I'm hoping to learn from you guys before I invest.
Click to expand...
Which ring gear, 8.25 or 8.75? With an OD transmission I would go with the 3.55. With the 4spd, 3.23 gears would be better. Smoking the hides is not a problem so a taller ratio will help with maintaining traction.
Fuel costs are up and down like a hooker's knickers these days, with a general trend as time passes of staying up. With that and the enviro loons activism in full swing, looking to squeeze as much mileage out of every drop of go juice is to be desired.
These clowns pushing "The Green Scheme" have their heads where the sun does not shine. The push to reduce emissions is to be admired, provided the result is attainable. Carbon or CO2 is not the evil in the room causing global warming or climate change. Earth has been slowly warming just a few degrees since the end of the iceage. The progression is like a slow motion spring in the northern states. Right now the daytime temperatures are slowly climbing. Snow in forests is barely starting to melt. It is melting away from tree trunks which the sun can warm. Snow and ice reflect the sun's rays back into space. Once ground is visible, the heating accelerates.
All the best with the 408 and picking the correct for you gear set. If you get new gears, break them in gently and change the oil after 500 miles. A magnet stuck to the inside of the diff housing will collect all the metal particles preventing them from getting between rotating parts.
 
Dale Davies said:
These clowns pushing "The Green Scheme" have their heads where the sun does not shine. The push to reduce emissions is to be admired, provided the result is attainable. Carbon or CO2 is not the evil in the room causing global warming or climate change. Earth has been slowly warming just a few degrees since the end of the iceage. The progression is like a slow motion spring in the northern states. Right now the daytime temperatures are slowly climbing. Snow in forests is barely starting to melt. It is melting away from tree trunks which the sun can warm. Snow and ice reflect the sun's rays back into space. Once ground is visible, the heating accelerates.
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Let's leave the politics to the N/P forum. This post isn't exactly helpful now is it?
 
ocdart said:
As said in an earlier post, rear gearing is application dependent. My current '69 Dart build is going to be a weekend car, not a daily driver. It's based on a 380-horse 360 crate motor that I plan to modify a bit to get over 400hp out of it.
Since it's going to be more 'toy' than anything I'm going with a 4.30 rear gear behind a 200-4R OD trans. I had the trans built as a manual-shift, reverse-pattern with a 2800-rpm lockup converter. Theoretically this combo will give me the best of both worlds. The 4.30 gears will be fun around town and the 0.67 OD will make them behave like 2.88 gears on the freeway. Others here on FABO with a similar lockup 200-4R have stated it almost feels like a 5th gear when lockup hits.
Other deciding factors for the 200-4R were that it fits in an A-body tunnel without major tunnel surgery and there is no computer involved with the transmission. Since mine was built as a manual-shift, I don't need to worry about a throttle valve cable or adjustment.
Click to expand...
Very cool. That will be a sweet setup. I love the 4.30's for ripping around town and future trips to the track. But I see a Gear Vendor OG unit in my future for extended highway trips lol.
 
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