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Stay with 5.13's or ??

BPerry

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Dec 7, 2021
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Now that the 351w is running steady, rig dropped down to something manageable, it's time to move to the next adventure.....

Rig is currently running stock C4, twin sticks, D44's, and 5.13 gears with lockers, on 33's.

I'm leaning toward a limited slip/true trac, with 4.11's.

Now this rig will see no hard wheeling and 98% pavement.

What do you professionals think?

20220129_191709.jpg
 

JeepGuy

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Aug 24, 2006
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5:13's for 33"s? What is your RPM at 55 with that set up?

I'll be running 302/c4 Dana 20 combo and was looking at 4:88's.
 
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BPerry

BPerry

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5:13's for 33"s? What is your RPM at 55 with that set up?

I'll be running 302/c4 Dana 20 combo and was looking at 4:88's.
I have no idea! I just finished the suspension drop, body drop, and new brakes all around and drove it last weekend...

With all the ice here in the south, I only got her up to 50. She sounded pretty wound up, but with dual cherry bombs and coming straight out under the doors, that can sound deceiving. I'll be putting a temp tach on this weekend.

When I got her, it was a mud rig on 42's...
IMG_0134(2).jpg
 

Broncobowsher

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That takes me from something I'm comfortable doing, to have no clue!! Lol
Instead of changing gears, put an overdrive transmission in. 4R70W is an easier option. You get the first 3 gears that are about like what you have now with the C4, and an overdrive for the highway. I had no issues doing long highway trips (Phoenix to Vegas) with 4.88s and 33s. 5.13s are only one little step further. Highway cruise would be like a set of 3.50 gears. Math says 3.59, but with a locked up convertor it will be less without the convertor slip. Yes, 5.13s can be good highway gears.
 
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BPerry

BPerry

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5:13's for 33"s? What is your RPM at 55 with that set up?

I'll be running 302/c4 Dana 20 combo and was looking at 4:88's.
Sorry for the long delay, just got done with the Sniper install, new rad, and many other what not's.......

She's pulling about 3400-3500 at 55 on 33's.

Runs like a beast though!
 

Apogee

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Nov 26, 2005
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OD trans swap or 4.11/4.30 gears would be the two best options as I see it. Gears would be the cheaper option if you can do the labor yourself, though I think the OD transmission would make the rig a much better driver. FWIW, before the most recent iteration on my EB, I was running 33's with 3.50 gears, 3-spd manual and a healthy 351W that pulls well off the bottom, and it was fun cruising around and could still hang on the interstate...but it sucked off-road and was hella hard on the clutch in the more technical stuff. While 4.11's would have been better in town, the 3.50's killed it at highway+ speeds, but it would still spin the tires if/when I wanted to off the line.
 

Broncobowsher

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The OD transmission will keep the beast feel with the low gears, but drop 1000 RPM off the highway speeds.
 

DirtDonk

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Would you do your own gear setup, or have it done?
I agree a trans swap is probably the best of both worlds, but if you're set on keeping the C4 then a gear change is what you are left with. The good news is that you can change just the rear for now to see how you like whatever choice you end up with (4.11 probably being the best compromise like you were thinking) and then do the front if you're satisfied.

If you do your own trans swaps, but take the differentials in to someone to set up new gears, the overall cost gap can get pretty narrow depending on your parts buying circumstances.
But if having someone do all the work, a trans swap can go into the stratosphere pretty quickly just like a gear change if you add lockers and other unnecessary stuff. Of course "unnecessary" being relative to what you intend to do with the truck. But lockers can get pretty pricey.
I like the Truetrac option myself.

I'm running 31's and 4.56's with an overdrive trans at the moment and it's kind of great. But I'm going down to 4.11's to see how that works out before eventually trying larger tires. With my setup I'm pretty sure the engine will be quite happy at the lower rpm levels.
But I should hit the Rubicon at least once while I'm rockin' the low gearing!

Good luck with the choices.

Paul
 
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BPerry

BPerry

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I would love to eventually do a tranny swap, but that's not in my "Self Imposed $ Cap For 2022-2023" Ha!

For a gear swap, I won't have to put it in the shop. So that seems the economical route at this point. My initial thought was 4.11's, but I seem to be tipping towards 3.89 rear and 3.92 front..... Very mild off-roading is all this cream puff will see.

Temp wise she's holding at 190-195 at 2500-2800 rpm, over 3K and she climbs to 205-207ish and returns to the previous. This is with a Sniper controlled Elc Fan kicking on at 195dg. Has new TP rad, 180dg high flow, new shroud.... The flex fan is stuck up all the way within the shroud, so I'm ditching that. Got new spacers and a 6 blade fixed on the way, I'm building it as a driver.

I already have a 09 Canyon 5.3 with 4.10's to play in... LOL

Tooo many toys!!

Thanks Gents!
 

DirtDonk

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All those years I drove my 71 daily and it always ran right where the thermostat was until I got to high-speed on the freeway or very slow on a long hot trail.
At between 3000 and 3500 RPM on the highway it would usually creep up to the 200-210 marks as well. And mine never overheated under any circumstances, so I don’t think that 200 is out of line at all. At least not for a stock setup.
And as we know now, 195 to 215 is right in the sweet spot for a modern engine.
 
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BPerry

BPerry

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All those years I drove my 71 daily and it always ran right where the thermostat was until I got to high-speed on the freeway or very slow on a long hot trail.
At between 3000 and 3500 RPM on the highway it would usually creep up to the 200-210 marks as well. And mine never overheated under any circumstances, so I don’t think that 200 is out of line at all. At least not for a stock setup.
And as we know now, 195 to 215 is right in the sweet spot for a modern engine.
Indeed, my goal is to operate at somewhere around those temps with just the mechanical fan. Then up the ele fan hot summer idles.

That's in a perfect world scenario...
 

bax

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Aug 22, 2005
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4.11 works great with the set up you mentioned. But I do like the idea of an overdrive transmission.
 

sprdv1

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Sorry for the long delay, just got done with the Sniper install, new rad, and many other what not's.......

She's pulling about 3400-3500 at 55 on 33's.

Runs like a beast though!
nice to hear....
 

B.ranch

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Apr 28, 2019
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Just pulled the 4.11s and installed 4.88s so happy with them, next to power steering prob one of best upgrades, ever since I pulled the top loader out and went to the np435 it seemed there was never enough power or to far between gears to make the power. Running 35/12.5 that measure only 34.
 
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BPerry

BPerry

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Went with 4.11's and new 31 spline axles. Couldn't be happier how it turned out and how much better it drives!! Motor doesn't sound like it's trying to come through the fire wall and grab me by the throat... lol

She's getting there, summer time in Arkansas!

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