rt-man
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Yup. I put 3.55s behind the 360 in my '73 SSP (245/60-15s on the back). Gives it a bit more attitude while still only being a cruiser...or it gives me a bit more attitude
Good bye highway gears. Hello 3.55
- Thread starter Airwolf222b
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Last fall, my friend and I were out riding around in his 72 440 Road Runner GTX. It has an automatic transmission and 3.55 sure grip rear axle. We both commented about how the 3.55 was the perfect all around gear for a Mopar.
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If I even could notice the 3.23 open to 3.55 SG swap (just a bit, but still noticeable) I can guess the huge WOAH you could exclaim with your swap after the first miles LOL
From seat of the pants feel I noticed the difference most in first gear on my basically stock, rather heavy 67 GTX with AC, power 215/75-15 radials and TF. With the 3.23 it could easily break the tires loose off the line in first just by hitting the throttle. But as the tires gradually started getting a grip I could feel and hear it start to pull the rpm’s back down I guess a little below the torque peak and then the tires would hook up and rpm’s start struggling back up climbing again.
With the 3.55s, just nailing the throttle (no need for loading the converter up on a 440), the tires start spinning and keep spinning long enough that once they hook the engine is apparently up on the torque curve and there’s no sensation of revs sagging and the engine lugging down. It’s just off to the races. I’m sure 2nd and 3rd are stronger too but it’s losing the rpm’s sag during first that was the most noticeable.
With the 3.55s, just nailing the throttle (no need for loading the converter up on a 440), the tires start spinning and keep spinning long enough that once they hook the engine is apparently up on the torque curve and there’s no sensation of revs sagging and the engine lugging down. It’s just off to the races. I’m sure 2nd and 3rd are stronger too but it’s losing the rpm’s sag during first that was the most noticeable.
andyf
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Yeah I did the same thing. I had an original B body Dana 60 under my '65 Coronet for 30 years. A guy I knew back in the '80's wrapped his 1969 GTX around a telephone pole. I bought the Dana 60 and the front disc brakes from him when he parted the car out. Think I paid $200 for both. 30 years later I sold the Dana 60 for $2000 and bought an S60 with disc brakes that was exactly the correct width for my car.
lemondana
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In the SLOW lane?
lemondana
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Yea, in 1973 when the speed limit was 55.
70ChargerRT
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I changed out Fred's gears to 3.55's when I got him to the point where I could drive him and that's
fine - as others have said, 65 is about 3000RPM going down the highway in 4th, but he isn't a distance
runner (least not, with all that LOUD 3" exhaust under there cooking the occupants...).
Pretty normal stuff in Mopar world, in other words. Makes perfect sense to me.
If I were to start travelling distances with him though, two things would need to change:
That infernal exhaust and those gears, both to more friendly highway equipment.
fine - as others have said, 65 is about 3000RPM going down the highway in 4th, but he isn't a distance
runner (least not, with all that LOUD 3" exhaust under there cooking the occupants...).
Pretty normal stuff in Mopar world, in other words. Makes perfect sense to me.
If I were to start travelling distances with him though, two things would need to change:
That infernal exhaust and those gears, both to more friendly highway equipment.
Na, just run it around 4200.
Doug
, I have a 4.10 Dana 60 in my 70 Charger R/T SE, it's a 4 speed car too. I will be going with some kind of overdrive transmission. I am leaning towards the A855 5 speed transmission. The car will have a 472 dual quad Fitech fuel injected Hemi in it.
mopar 3 B
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You've got to be crazy. If I still had them I would post some turnpike tickets. 40+ miles in less than twenty minutes with 3:54's.
mopar 3 B
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Not sure what your complaining about. My Ram has 5.56 gears and has been road tripped on the highway.
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Is already available?
It has been told has been out of stock for looooong time after several mechanic issues and customer claims and returns.
I believe another vendor is offering them now.
33 IMP
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I've got 180,000 miles on the 55 Chevy I drove in high-school, ..... with factory 3.55 gears (3speed sticks got 3.70s, 3 speeds with overdrive got 4.11s. Iron,powerglides got 3.55s) 65-70 mph on the freeway was a daily occurrence for a couple decades.
Krooser
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My Coronet has a 2.94 gear but, with the 3.09 first gear in the aluminum 833 perhaps 225/70-15 tires, the off throttle acceleration will be OK. And I think the 70 mph revs will be pretty low.
I'm hoping to get 20 mpg on the hwy with the 318.
Time will tell.
I'm hoping to get 20 mpg on the hwy with the 318.
Time will tell.
Butch Harley
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I also run 3.55 in my RR also run a passion performance 4 speed with .73 fourth. At 75 mph 2K
JC Boatguy
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I was so happy to find out my plymouth I got from Dave had a 3.55 SG!!!
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