What Gears Should I Choose?

[Av8r]

Is your buddy's truck a 68RFE? Basically you have 2 OD gears 5th and 6th. 4th if I remember right is 1:1 in a 68RFE. I dont know exactly where 1:1 would put the rpm if you ran up to 65 with 4:10s but I'm saying make sure you compare apples to apples and does he have the same trans

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He does have a 68RFE, his is a 2011 model and mine is a 2017. I thought that sounded a little high to me too. I might have to take a ride with him and see.


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[RATLIN'HP]

He does have a 68RFE, his is a 2011 model and mine is a 2017. I thought that sounded a little high to me too. I might have to take a ride with him and see.


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Yeah even 4.56s with 35s is 1800ish at 65-70 mph.

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[RATLIN'HP]

If he ran in 5th gear which is (.82:1) at 65 mph with 4.10s and 35s, it would be over 2k rpm.

Close to 2100 actually.

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[Av8r]

I appreciate everyone's help and input, I'm going to do a little road testing to see how accurate that calculator is.

If it's on point I think I might go with the 4.10's or the Nitro 4.11 kit.

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[SyN]

Thank you for the calculator - that will be quite handy in the future.

Question: What is the (sweet spot) torque range of the 6.7L with the 68RFE behind it --->{1600-1800 rams}?

EDIT:
Ok - I found torque specs for my 2017 = 800 lb-ft @ 1600 rpms

I'm not a fan of towing in 6th gear & I will not be towing over 65mph so my 33" tires & 3.42s will put me @ 1856 rpms.

I now see what Cummins & FCA was possibly thinking & why they chose 3.42s.
Feeling a bit better about my 3.42s & the .82:1 (5th gear)!

I wish 3.73s would have been given as a option with the 2500s.

I'm not in a rush to get no where fast - I'm content towing in 5th gear and keeping my 6.7L in the best rpm range.
If the family & I was towing across the country and towing over 20K lbs (3500 DRW) - I have a feeling I would highly request the 4 range gearing.

Even Though: 3.73 or 4.10 would be possibly a better option.

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[RATLIN'HP]

MPG is usually best around that 1600 rpm range in my opinion also.

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[Av8r]

Oh yeah, 4:10’s is where it’s at.

I’m watching my buddy’s truck for him while he’s out of town.

He has 4.10s in his and it feels like a rocket ship compared to mine.

At 60-65 his RPM range is about 1,600-1650.

I think I know what gears I’m going to go with now.


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[Murph]

Is your buddy's truck a 68RFE? Basically you have 2 OD gears 5th and 6th. 4th if I remember right is 1:1 in a 68RFE. I dont know exactly where 1:1 would put the rpm if you ran up to 65 with 4:10s but I'm saying make sure you compare apples to apples and does he have the same trans

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Damn I love this site.

Smart thread fellers, GREAT info and exchange! ME GUSTA!!

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[f18framer]

Glad I read this thread.

I am looking at the exact same thing.

I think I, just might copy you LOL.

I drive the same roads I work in VB and live in suffolk.

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[Av8r]

Glad I read this thread.

I am looking at the exact same thing.

I think I, just might copy you LOL.

I drive the same roads I work in VB and live in suffolk.

f18framer I sent you a PM.

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