3.55 to 3.92 - is it worth it?

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Riverside California
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2018 2wd
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HEMI 5.7 Revolution 4.88s
Don't forget the front differential. Needs to change too.
One reason I chose a 2wd , price was $10k more and then to regear because I eventually wanted 37s ...

So I saved money on the truck and on regearing since I only had to get the rear done and not the front lol ....
 

67440dodge

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Not in a truck but in a old car, I went from 3.55's to 3.91's and yes, there was a HUGE difference in acceleration. Shaved over a second off my 1/4 mile time and with a 727 Torquflite I went from a 2nd gear chirp to spinning the tires into 2nd even with street slicks.

Downside was highway RPM's... Almost 4 grand at 70MPH, hence buying a Gear Vendors Over/Under Drive for it..
 

Wild one

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Not in a truck but in a old car, I went from 3.55's to 3.91's and yes, there was a HUGE difference in acceleration. Shaved over a second off my 1/4 mile time and with a 727 Torquflite I went from a 2nd gear chirp to spinning the tires into 2nd even with street slicks.

Downside was highway RPM's... Almost 4 grand at 70MPH, hence buying a Gear Vendors Over/Under Drive for it..
The good old days of 3 speed's with a 1:1 high gear,lol.I had 4.88's with 28" tall tires in a 68 Camaro as a kid,they were great till a 100 mph,plus you got to know every gas station attendent with-in a 50 mile radius,lol
 
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HEMI 5.7 Revolution 4.88s
The good old days of 3 speed's with a 1:1 high gear,lol.I had 4.88's with 28" tall tires in a 68 Camaro as a kid,they were great till a 100 mph,plus you got to know every gas station attendent with-in a 50 mile radius,lol
My Dad had a 66 Chevelle on 4.88s ... I remember driving with him on the LA freeways in the early 80s going down towards the 210 into Redlands lol .... there was nothing out there at that time and you always found Stingrays, Novas, Camaros, Trans AMSs lol ... oh man those drives where so much fun as a kid lol .....
 

Wild one

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My Dad had a 66 Chevelle on 4.88s ... I remember driving with him on the LA freeways in the early 80s going down towards the 210 into Redlands lol .... there was nothing out there at that time and you always found Stingrays, Novas, Camaros, Trans AMSs lol ... oh man those drives where so much fun as a kid lol .....
A buddy of mine had 5.13's in a 69 Dart Sw inger,with a 3600 convertor,and a very healthy 340 with a 125 shot,the car was violent to about 90 mph,lol On a light to light street race,there weren't many cars that'd stay with his little S winger,lol. Apparently sw inger goes against community standards,lol
 
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Engine
HEMI 5.7 Revolution 4.88s
A buddy of mine had 5.13's in a 69 Dart Sw inger,with a 3600 convertor,and a very healthy 340 with a 125 shot,the car was violent to about 90 mph,lol On a light to light street race,there weren't many cars that'd stay with his little S winger,lol. Apparently sw inger goes against community standards,lol

Oh I can only imagine that ride ! lol ... Friend and I wrapped a Grand national he just regeared and he had no FAWHKEN clue what he did when he slammed the pedal down lol .... I ain't gonnah lie though, I was shewten' bricks haha !
 

dhay13

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lol. I had a 1970 Olds W31 with factory 3.91 and Muncie M21. Wasn't bad even on the highway but back then 55 was the max limit anyway. But I had a 1969 Chevelle that initially had 3.73's on my first iteration then bumped to 4.10 then to a KTRE 4.56 9" with spool and Moser axles. Not much fun on the street with the spool but it was street legal but spent most of it's time on the track.


70-W31-2.jpg
69-Chevelle-black.jpg
Same Chevelle before re-paint
Chevelle.jpg
 

LugsLeadOut84

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A buddy of mine had 5.13's in a 69 Dart Sw inger,with a 3600 convertor,and a very healthy 340 with a 125 shot,the car was violent to about 90 mph,lol On a light to light street race,there weren't many cars that'd stay with his little S winger,lol. Apparently sw inger goes against community standards,lol

Wow....My first car was a '72 Dart Sw*nger that we yanked the good 'ole slant 6 out of and put a 318 in. While it wasn't a beast as I'd imagine the 340 was but it was respectable around high school and town.
This was in the 80's long before cellphones and I only remember having 1 or 2 pictures of it that I wish weren't long gone. It was sent up from my Grandmother in Florida barely driven, no rust and was black (which was rare). My uncle owned a wheel, rim & brake shop, knew all the mechanics in the area and would barter to help me outfit this thing. Mags, white-letter tires, air shocks in the rear and the new 318. It was sort of unique as there weren't a lot of worked Darts around. It was so much fun.
 

Intense-Dakota

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Hemi 5.7
I have a 2017 Rebel with 8 speed and 3.92. I have owned many Rams and a Dakota with 3.55 gears and I go early wouldn't ever want to go back. I love the extra pep and pull that I get and even towing with the 3.92 gears on long trips isn't bad with the 8 speed.
 

Mike Garvey

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Biggest problem is your stuck buying whole center/dif assembly. We make the ram drive units (ZF) and front rings are welded not bolted
 

Marine Les

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I want the 3:92s to get my Pentastar into 8th gear sooner as well as for towing. Guys w/3:92s and the v6 are showing same mpg for daily driving. To keep the cost down i will look for a late rear end with the 3:92s in a salvage yard. should be very inexpensive if I sell or swap the 3:55s.
 

Wild one

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Wow....My first car was a '72 Dart Sw*nger that we yanked the good 'ole slant 6 out of and put a 318 in. While it wasn't a beast as I'd imagine the 340 was but it was respectable around high school and town.
This was in the 80's long before cellphones and I only remember having 1 or 2 pictures of it that I wish weren't long gone. It was sent up from my Grandmother in Florida barely driven, no rust and was black (which was rare). My uncle owned a wheel, rim & brake shop, knew all the mechanics in the area and would barter to help me outfit this thing. Mags, white-letter tires, air shocks in the rear and the new 318. It was sort of unique as there weren't a lot of worked Darts around. It was so much fun.
Nothing wrong with the little 318,it was Chryslers lowest warrentied motor built,basically bullet proof. Usually the body rotted off anything with a 318 before the little motor died,lol.With the right parts they were fairly quick,i knew of a few 318's that had the 340 J heads and factory 275 hp 340 cam in them,and in a light Duster/Dart etc.,they were surpriseling quick,while still getting decent milege
 

crazykid1994

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Nothing wrong with the little 318,it was Chryslers lowest warrentied motor built,basically bullet proof. Usually the body rotted off anything with a 318 before the little motor died,lol.With the right parts they were fairly quick,i knew of a few 318's that had the 340 J heads and factory 275 hp 340 cam in them,and in a light Duster/Dart etc.,they were surpriseling quick,while still getting decent milege
My fiancées truck was a 97 with the 318. At 165,000 miles on it and still ram like a champ. Oil changes, Spark plugs, wires, dizzy, distributor, water pump, and plenum pan/gasket were all that was ever done to that motor. It did have a new trans at around 80-90,000 before she got the truck though. 46re. Needed a new body but otherwise was a great truck. She drove it home after the plenum gasket failed. Sucker burned almost a quart of oil on the way home. Honestly not sure how it stayed running. Blowing smoke. Killed the O2 sensor and the cat was basically clogged but it kept running.
 

El_Lobo_Gris1500C

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I have had a 2019 Classic with 3:55 gears, and traded it in for a 21’ Classic with the 3:92 gears now, and I’ve only run the stock 20” wheels with factory size tires. The 19’ was a 6 speed column shifter, the 21’ is a dial shifter 8 speed trans. I don’t notice that much difference over all with normal driving, but when I really punch it from a stop the 3:92 seem to get up and go a little quicker.

The trade off is I would prefer the 3:55 for highway driving, in that truck I was probably around 1500rpm cruising between 100km - 110km/hr. With the 3:92 at those speeds I’m at around 1900rpm - 2000rpm which isn’t that bad in a truck with factory exhaust, except I put a Flowmaster 50HD muffler on the truck and you notice a huge difference with noise at the higher rpm cruising. I avoid 98km/hr - 108km/hr because of this added noise, and stick to either under 95km/hr or closer to 115km/hr+ to keep the drone and noise down. Or I have to limit the gearing to 7th to keep the rpm up over the annoying 1900rpm zone.

I guess with the larger wheels/tires that will make a difference and affect everything, but if I could choose again I would probably just go with the 3:55’s personally.
 
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I've got factory 3.92's on my '17 with 35's and the 8-speed. In 2WD I can burn rubber! Though try not to, these BFG KO2's aren't cheap. I'll leave the 1/4 mile runs to my Jag F-type R. But, for towing, it for sure makes a difference. I used to tow with my Jeep GC, which I think has the same trans and 3.54 gears (though it is fulltime 4wd), but this truck makes a noticeable difference, especially when taking off from a stop. Same trailer, same hitch.
 
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