3:23 vs. 3:55? Need opinions

dspaulding70 · February 10, 2008, 10:37:59 AM

I have the option to choose either the 3:23 or the 3:5 gears for my 8 3/4 (489 casing) sure grip rebuild. I will have a rebuilt 440 pushing close to 475 hp when it is finished. I am looking for a street cruiser but with enough quickness to not get embarrassed but do not want to have the engine whinning to cruise 70mph.

I have to make the decision by Tuesday so I appreciate your feedback.

Darrell

68 CHARGER R/T · February 10, 2008, 11:08:15 AM

i'd go with the 3:55, and put in a nice stall convertor

firefighter3931 · February 10, 2008, 11:19:32 AM

The 3.55 axle works nice especially if you plan to use a 28in tall tire because the increased tire height will knock some rpm's out of it on the highway. If i was buying new the 3.55 would be my choice out of those two ratios....but not my first choice.

Ron

Nacho-RT74 · February 10, 2008, 11:20:18 AM

diff is, around 10% more revs to get same speed, but will mean also arond 10% more torque at same speed... also 10% less top speed. also more less 10% less gas mileage

maybe also around 10% more fun ?

. I'm changing from 3.23 open to 3.55 suregrip and will know personally the change

resq302 · February 10, 2008, 11:27:59 AM

I changed out my ring and pinion last year from the original 3.23 to 3.55 and found it to be exactly as Nacho said. The 3.55 gives it a little more pep and a little more fun off the line. Around 70 mph I think the RPMs are around 3000 or close to it.

Ghoste · February 10, 2008, 12:54:43 PM

I'm 100% with Ron, not my first choice but of the two offered, the 3:55 will be a lot more suitable for you.

General_01 · February 10, 2008, 01:12:31 PM

Go with the 3.55's. I have 3.55's in the Bee. When I got the General I thought it wouldn't be that big of a deal having 3.23's. I swapped the 440 from the Bee to the General and you can tell the difference. Same motor, but it feels more sluggish off the line in the General.

70charginglizard · February 10, 2008, 01:28:47 PM

I have to agree with the others if what your doing with the motor and how your using the car is true.

I myself am going to 3:23's but again, My aim is more towards cruisability a little more decent gas mileage on long trips and not as much high performance.

I myself have heard from others that 3:55 can be a bit noisy on long trips so you'll have to take that in consideration.

You have to make the choce though. It's untimately your call.

Ghoste · February 10, 2008, 01:54:01 PM

One man's noise is another's highway song.

70charginglizard · February 10, 2008, 02:30:51 PM

Quote from: Ghoste on February 10, 2008, 01:54:01 PM
One man's noise is another's highway song.

Point well taken

john108 · February 10, 2008, 08:12:30 PM

I have a 2004 Dodge Big Horn Hemi Quadcab pick-up with 3.92 gears. At 70 mph, it is at 1900 rpm but it has trouble getting out of its own way!

resq302 · February 10, 2008, 08:13:23 PM

Quote from: john108 on February 10, 2008, 08:12:30 PM
I have a 2004 Dodge Big Horn Hemi Quadcab pick-up with 3.92 gears. At 70 mph, it is at 1900 rpm but it has trouble getting out of its own way!

And that probably has a 5th gear overdrive in it if it is manual.

Ghoste · February 10, 2008, 08:24:42 PM

I know my 4:10's are turning a lot more than that at 70mph... and mine can't get out of it's own way either.

mikesbbody · February 10, 2008, 08:26:16 PM

another vote for 3.55's i have them and drove a charger similar to mine with 3.23's..man, did that feel slow off the line.

Charger Steve · February 10, 2008, 10:31:25 PM

I recently changed my rearend gears in my 68 Charger 383 4bbl. from 3:23 to 3:55 and am very pleased with the results. More responsive on the low end but more rpm's at highway speed, but worth the tradeoff. The difference in miles per gallon is insignificant in my opinion.

doctorpimp · February 11, 2008, 08:57:35 AM

3.55 would be the best choice for you IMO.

Depends on transmission, tires etc.
That was too little gear for my wife's Barracuda with Keisler. Had to go to 3.91 - even that is high with the overdrive.

Mike DC · February 12, 2008, 12:34:00 AM

Any musclecar I ever build with "cruiser" in its job description needs to have an overdrive of some sort. Either that or a 2.94 rearend.

Cruising on most interstates these days, it calls for a good 75-80 mph just to hold even with the rest of traffic.

70charginglizard · February 13, 2008, 10:35:59 PM

Talkin about third members....

the one I just bought on e-bay just showed up today.

Cleaned all the dirt off of it and it looks pretty dang nice now-

By kels70charger

Little exterior paint and a few bolts and we should have two wheels spinning.

Now all I gotta do it put it in.

71charger_fan · February 14, 2008, 01:05:55 PM

I've got a rebuilt 400 in my '71 that runs 14.4s in the quarter. That's about what 440 cars ran in the road tests back in '71. I've got 275/60-15s and a 3.23:1 gear. It's awesome on the highway. I got the gears for free, so I used them. They were an incredible step up from the 2.45 equipped 8 1/4 I took out of the car. However, if I was doing it again today, I'd go with 3.55s or 3.73s.

70charginglizard · February 14, 2008, 01:54:27 PM

Well for me its a freebee
I'll always have the one I'm dropping (the 2:76 non suregrip) as a backup or rebuld for a 3:55.
For now I'm gonna try the 3:23's/

dspaulding70 · February 15, 2008, 04:50:08 PM

So what would the rpm's be to run about 70mph with each of these?

Ghoste · February 15, 2008, 05:33:11 PM

What size tires?

Nacho-RT74 · February 15, 2008, 05:52:01 PM

http://www.moparts.com/Tech/tech/img/AUTOMATICchart.xls
http://www.moparts.com/Tech/tech/img/4SPEEDchart.xls

and:

http://vexer.com/68rt/speed.html

some missmatch between them but at least an aprox

Just 6T9 CHGR · February 15, 2008, 06:21:38 PM

I went from 3.23's to the 3.55's & won't look back!

694spdRT · February 15, 2008, 07:42:45 PM

I went from 2.72's to 3.55's in the '68 and talk about a difference. I swear 2nd gear seemed higher with the 2.72's than drive with the 3.55's.

71charger_fan · February 16, 2008, 04:48:40 AM

With my combo, I've never gotten out of second gear in the quarter mile. Maybe that's a good thing, I don't know, but I go through the traps before I hit my shift point for the 2-3 upshift.

Ghoste · February 16, 2008, 09:52:59 AM

Unless you're moving through there so quickly that you only need two gears, it means you're leaving some on the table and that table is parked back at the starting line.

Go Hogs Go · February 16, 2008, 01:50:26 PM

In 4th gear with my 3:55 I'm turning 3200 rpms @ 70. My 3:23 car in 4th gear turned 2800 @ 70.

69_500 · February 16, 2008, 08:05:38 PM

I guess you all would call me the odd ball here, but I'm actually going to go the opposite direction of what everyone else seems to be saying.

Me personally I'm debating over going with a 3.23 or even a 2.76 rear gear in my car this spring. Right now it has a 4.11 gear ratio in the rear end, and man that is a bear on the highway for a long cruise to an out of state Car show. Being that I don't want to trailer my car to any show I go to, I'm thinking of going for the 2.76. Depends on which one I find first, and for the best deal.

General_01 · February 16, 2008, 08:26:22 PM

Going from 4.11 to 2.76 is going to be quite a shock to your system.

I am actually contemplating changing the 3.55 in th Bee to a 3.73. On the Speed/RPM calculator it only means about 200 rpm's more at 70mph, but more fun off the line.

69_500 · February 16, 2008, 08:36:35 PM

A shock to the performance system yes, but MUCH more enjoyable for the family when cruising 300+ miles to a show. Right now the car is turning about 3,800 RPM at 70 MPH on the highway. I'm thinking with the 2.73's that would drop down to around 2,300, and with the 3.23 would put me around 2,600 or so. Either way a lot less road noise, which makes the wife happier, considering that the AM radio doesn't pick up stations for very long periods of time.

General_01 · February 16, 2008, 08:40:49 PM

Quote from: 69_500 on February 16, 2008, 08:36:35 PM
A shock to the performance system yes, but MUCH more enjoyable for the family when cruising 300+ miles to a show. Right now the car is turning about 3,800 RPM at 70 MPH on the highway. I'm thinking with the 2.73's that would drop down to around 2,300, and with the 3.23 would put me around 2,600 or so. Either way a lot less road noise, which makes the wife happier, considering that the AM radio doesn't pick up stations for very long periods of time.

I hear you about the road trips. As far as the wife goes, sounds like you need to get her an Ipod for her next birthday.

Duey · February 16, 2008, 08:49:32 PM

bahhh....4.10!

Ghoste · February 16, 2008, 10:13:45 PM

Which is why I don't run 70mph on the freeways I suppose. If I did a lot of long distance stuff I'd be singing a different tune too.

694spdRT · February 16, 2008, 11:08:13 PM

I agree that if you do a lot of long distance driving the 3.23 or preferably 2.73's are a great choice. The 2.73's in my Charger would cruise at 1800rpm around 60 mph and I got around 18mpg with the old 383.

The plan for Challenger I am building is a 833OD and 3.23's.(or roughly a 2.35 final drive)

2Gunz · February 21, 2008, 03:06:15 AM

I just swapped out my 2.73

I could do like 40mph at idle.

And around town I almost never left 1st.

So far I like the new 3.55 better.

Belgium R/T -68 · February 22, 2008, 02:05:26 AM

Am I looking forward to my new 3,55 set up when I read your comments

Just like dspaulding70 I am getting my -68 R/T a fresh rebuild with approx the same
HP range and h**l of a lot of torque. Going from original low compression pistons, worn out heads and cam, swapping the 2,76 to the 3,55 will feel like a horsekick if I
read the comments here.

73chgrSE · June 07, 2008, 03:29:27 PM

I went with 3.73 and i have mixed feelings about it. It's kinda weird, at night i'm sure i did the right thing but during the day i feel like i should have went with a 3.55. I have to get some taller tires before i make my final decision, it maybe just right. Going from a 2.76 open to a 3.73 suregrip feels like a just bought 100 hp though.

News:

3:23 vs. 3:55? Need opinions