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Re: Best Street Gear Ratio?? -HELP
[Re: Mr.Yuck]
#60650
05/21/08 11:36 AM
05/21/08 11:36 AM
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Joined: Mar 2003
Posts: 3,358
Berwyn, IL
challenger70
master
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master
Joined: Mar 2003
Posts: 3,358
Berwyn, IL
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Quote:
depends on how much highway driving you are going to do. What are the engine specs..and on and on. 3.91's are a good gear for a b-body. With a set of 275/60/15's you can cruise at 70 no problem. 3.55's are ok but they are dog gears compared to 3.91's...as are 3.23's. Try the 3.73's they are pretty new to mopars. Let us know how they run.
 I have 3.91's on 28" tires and drove my car from Sanfrancisco to Chicago no problems and they have some pretty high speed limits out west.  It can get a little buzzy on the highway but it isn't terrible below 70-75.
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Re: Best Street Gear Ratio?? -HELP
[Re: HotRodDave]
#60652
05/21/08 11:56 AM
05/21/08 11:56 AM
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Joined: Apr 2008
Posts: 1,195
Snowing in the north!
Dart 340
moparts member
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moparts member
Joined: Apr 2008
Posts: 1,195
Snowing in the north!
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Quote:
Quote:
i drove with 4.30's on the hiway with a 28" tall tire at 60-65mph.. wasn't all that bad.
Why would anyone want to drive just 60 or 65 ? Even 70 is not gonna keep up with trafic around here 
Even with my 2.76 gears and lock-up trans I am turning 3000 @ 80mph.
I have to agree. I spend as much if not more time in a 70 MPH speed limit zone than city. If you can't light the tires up maybe you need a tune up...
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Re: Best Street Gear Ratio?? -HELP
[Re: Dart 340]
#60653
05/21/08 01:15 PM
05/21/08 01:15 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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if you plan on doing any freeway driving, I'd go 2.94's or 3.23's w/28" tires.
my car with 3.55's and 27" tires was turning 3k RPM at 70mph without the OD tranny, and it got tiring after about 30 minutes at that speed....now I cruise at ~2200 RPM at 70 with my A500...
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Best Street Gear Ratio?? -HELP
[Re: A4SixtyNineRR]
#60654
05/21/08 01:45 PM
05/21/08 01:45 PM
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Joined: Jan 2003
Posts: 5,439
So Cal
Sinitro
master
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master
Joined: Jan 2003
Posts: 5,439
So Cal
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Quote:
Hey guys I want to get everyone's opinion on this one. I have a '69 RR that I am currently restoring and I am trying to decide what gear ratio to use in the rear end (currently a 3.23). I want to be able to use it on the street for cruising, but want to be able to light up the tires when I feel the need. The obvious choices are 3.55, 3.73, or 3.91 for the set up but I have only driven a 3.91 other than my 3.23. I am afraid a 3.91 might be too low and give me too high of rpm's with whining going down the highway. SO I am thinking that narrows it down to 3.55 or 3.73. Any opinions on which is better or is there even a noticeable difference between the two? Thanks for helping out!! 
Before selecting a gear ratio..
I would ask a couple of questions..
1. Type of trans; Stick or Auto
2. If Auto, type of converter & stall speed
3. Engine build like what cam, compression
My experience with the Mopars is that the 3.23 is a great gear, more for cruisin. If the engine is built somewhat like bigger cam (low vacuum) I would step it up to a 3.55. As the engine is built up, typically the HP moves upward while dropping the lower end torque. Also What type of driving also is pertinent here, country road cruisin or stop & go..
Just my .. 
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Re: Best Street Gear Ratio?? -HELP
[Re: Jeff_383]
#60659
05/21/08 04:18 PM
05/21/08 04:18 PM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
When put behind 600lbft. of torque 3:55's are NOT a dog gear.
doubt he'll be pushing close to those numbers..and whatever 3.55's can do 3.91's can do better.
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Re: Best Street Gear Ratio?? -HELP
[Re: terzmo]
#60661
05/21/08 04:57 PM
05/21/08 04:57 PM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
I reccommend 355 with a tire size of 25 or 26 inches...that roadrunner will accept some meaty shoes and what I would do is run a drag/street tire of 30 inches hieght and run 391 or 410.Either way you will light them and have a very nice top end
yeah a 25-26" tire on the back of a b-body looks all wrong.
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Re: Best Street Gear Ratio?? -HELP
[Re: HotRodDave]
#60663
05/21/08 08:27 PM
05/21/08 08:27 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Quote:
i drove with 4.30's on the hiway with a 28" tall tire at 60-65mph.. wasn't all that bad.
Why would anyone want to drive just 60 or 65 ? Even 70 is not gonna keep up with trafic around here
Even with my 2.76 gears and lock-up trans I am turning 3000 @ 80mph.
cause i'm not in a hurry to go anywhere.
if i really, really have to go on a superspeed
long trip.. 20mins and the 2.76's are in. 
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Re: Best Street Gear Ratio?? -HELP
[Re: Jeff_383]
#60664
05/21/08 08:29 PM
05/21/08 08:29 PM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
My "street driver" has 600 ftlbs.
do you have 3.55's and an auto?
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Re: Best Street Gear Ratio?? -HELP
[Re: Mr.Yuck]
#60665
05/21/08 08:51 PM
05/21/08 08:51 PM
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Joined: Jan 2004
Posts: 877
Pittsburgh, Pa
Jeff_383
super stock
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super stock
Joined: Jan 2004
Posts: 877
Pittsburgh, Pa
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YES
Sorry caps lock was on, yes
Last edited by Jeff_383; 05/21/08 08:53 PM.
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Re: Best Street Gear Ratio?? -HELP
#60667
05/21/08 10:19 PM
05/21/08 10:19 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
cause i'm not in a hurry to go anywhere.
if i really, really have to go on a superspeed
long trip.. 20mins and the 2.76's are in.
Kinda defeats the purpose if you have to change every time you want to go on a longer highway trip tho. I know some guys do the swap quick but I'm not that good.
I've got 3.55's with a 27" tire and it's okay, but still revving high for me at 60mph. Doesn't really matter that much for me because I don't take my car out on the highway much anyway. 3.55's are a compromise gear. They'll cruise on the highway and they'll race down the strip, but they won't do either one that well. However I still think they're a better middle ground than 3.23's. But if you've got 3.23's already, is it worth the $ to change to 3.55's? IMO, no. Play with the speed/rpm calculator linked to a few posts up and get a feel for what you can handle. I think 3.73's would give me a little more punch and not give up much on the highway, but again, not worth the $ for that little of a change.
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